The Games and Puzzles Journal — Issue 24, September-December 2002

This issue is devoted entirely to some excellent work by Awani Kumar that was sent to us by e-mail on 3rd August 2002. Where successive tours are very similarly numbered the editor, to assist in recognition, has highlighted in the second tour cells that differ from the numbering in the first tour. The author is at the following postal address: Awani Kumar, B-4, Forest Colony, Vibhuti Khand, Gomti Nagar, Lucknow - 226010, INDIA.


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Sections on this page: (26) The Raja of Mysore's Tour and Related Tours. (27) Some New 'Almost Perfect' Magic Tours. (28) Two Tours Nearest to 'Perfection'. (29) A Tour by Murray and Related Tours. (30) Enumeration of Magic Tours. End

é (26) The Raja of Mysore's Tour and Related Tours.

The very first magic Knight’s Tour on 12x12 board (Fig.1) was constructed by Krishnaraj Wadiar, Raja of Mysore, India, before 1868. The author has observed that it is a rich mine of re-entrant magic tours. Hundreds of 'simple magic tours' (only rows and columns are magic, not diagonals) can be derived from it by modifying and connecting the sectors. Fig.1 can be divided into 9 sectors, each of 4x4 size, as shown in Fig.2. By modifying sectors E and F, another magic tour (Fig.3) can be obtained. Similarly, Fig.4 and Fig.5 can be obtained by modifying sector H of Fig.3. All these are 4-fold cyclic magic tours, that is, they remain magic when numbered from 37, 73 and 109. Fig.6 is unique in the sense that the sum of the diagonals (=1268) is minimum in it. A host of magic tours, with sum of the diagonals being twice the magic constant, can be constructed. Fig.7 and Fig.8 are just two examples. Fig.9 and Fig.10 show the magic tours with one diagonal (= 872), nearest to the magic constant (= 870).

ABC
DEF
GHI
Fig. 2.
7174143210342113321053611138
1421707311431104411123910835
7572314443102291163310637110
4141766930115441014010934107
77681396994611728955012322
140578671182710045122239451
65807138479825120499621124
81376679261194897241215293
81649136856012916895612520
101358461132138857128179253
638217312598615130559019126
134116283141315887181275491
Fig. 1. D1=608 D2=980
7174143210342113321053611138
1421707311431104411123910835
7572314443102291163310637110
4141766930115441014010934107
77681396992811748121509522
140578671184510025962312251
65807138279847120491242194
81376679461192697249352123
81649136856012916895612520
101358461132138857128179253
638213312598615130559019126
134116283141315887181275491
Fig. 3. D1=648 D2=1020
7174143210342113321053611138
1421707311431104411123910835
7572314443102291163310637110
4141766930115441014010934107
77681396992811748121509522
140578671184510025962312251
65807138279847120491242194
81376669461192697249352123
81649136856015130895612520
101358461141318857128179253
638213312598612916559019126
134116283132135887181275491
Fig. 4. D1=648 D2=1020
7174143210342113321053611138
1421707311431104411123910835
7572314443102291163310637110
4141766930115441014010934107
77681396992811748121509522
140578671184510025962312251
65807138279847120491242194
81376669461192697249352123
81649136856012916895612520
101358461141318857128179253
638213312598615130559019126
134116283132135887181275491
Fig. 5. D1=648 D2=1020
6310811366587914069142752
821356498013766576172143
1162133847781396814170374
1348312611386767747314471
5914851324711899281013043114
8613160139827461174411510231
15581298811948251002942113104
1308716572697120451161033241
5512889209324491223340105112
9017561255212196231081112437
1275419922194123503936109106
1891126531245122951101073835
Fig. 6. D1=824 D2=444
1954911262152123943538107110
9012720531249350231061093639
5518125925122951223734111108
1288956179612124491121054033
5716129882548971202944113104
8613158159811928451021153241
13608713047261171004330103114
1328514591189946271161014231
8312611366567914069144732
621338498013966576370143
1182135641377876814172174
1346310818671387747514271
Fig. 7. D1=720 D2=1020
1954911262152123943538107110
9012720531249350231061093639
5518125925122951223734111108
1288956179612124491121054033
5716129882548971202944113104
8613158159811928451021153241
13608713047261171004330103114
1328514591189946271161014231
8312611366587714069144732
621338498013768576370143
1182135647661397814172174
1346310811387966747514271
Fig. 8. D1=720 D2=1020
1954911262152123943538107110
9012720531249322511061093639
5518125924924951223734111108
1288956179612150231121054033
15581298825481191002942113104
1308716571209726451161033241
5914851324711899281013043114
8613160139827461174411510231
6112133847781396814172174
1348310631386767747514271
1162811366587914069144732
821356498013766576370143
Fig. 9. D1=1058 D2=872
1954125922152123943538107110
1269120531249372511061093639
5518891284924951223734111108
9012756179612150231121054033
15581298825481191002942113104
8613116571209726451161033241
5914871304711899281013043114
1328560139827461174411510231
6112133847781396814172174
1348310631386767747514271
1162811366587914069144732
821356498013766576370143
Fig. 10. D1=936 D2=872

é (27) Some New 'Almost Perfect' Magic Tours.

T.H. Willcocks, H.J.R. Murray, E. Lange and G.P. Jelliss have also constructed magic knight tours on 12x12 board but a 'perfect magic tour' (with both the diagonals equal to magic constant) is still elusive. Willcocks has given three 'almost perfect magic tours' (with one diagonal equal to magic constant). The author has constructed 11 new 'almost perfect magic tours' shown in Fig.11 to Fig.21. Their reverse tours are also 'almost perfect magic tours.'

832613348852412952892012754
134478425132498821128539019
278245136238651130179255126
461352881501312287561251891
298013744991011962931612358
421397831118639811124579415
793043138910061120139659122
140413277641171297601211495
337614140101865116107267114
381433673110711081661151063
753439142710211170510411368
144377435721096103112694105
Fig. 11. D1=1016 D2=870
832613348852412952892012754
134478425132498821128539019
278245136238651130179255126
461352881501312287561251891
793013744991011962931612358
138438029118639811124579415
317841140910061120139659122
421393277641171297601211495
337614140101865116107267114
381433673110711081661151063
753439142710211170510411368
144377435721096103112694105
Fig. 12. D1=1016 D2=870
812813546872212952892012754
136458227130518821128539019
298047134238657124179255126
441372683501311693561251891
793013348852412358951412160
138438425132499415122599613
317841140510467114710261120
421393277681136103661151297
337614140105469112101811962
381433673110711081116659811
753439142310611170910063118
144377435721092107641171099
Fig. 13. D1=888 D2=870
832613348852413150872212952
134478425132498623130518821
278245136139659122159453128
461352881601211495581232089
298013744971211962931612754
421397831120619811124579019
793043138910063118179255126
140413277641171099561251891
337614140101865116107267114
381433673110711081661151063
753439142710211170510411368
144377435721096103112694105
Fig. 14. D1=1016 D2=870
832613348852413150872212952
134478425132498623130518821
278245136139659122159453128
461352881601211495581232089
793013744971211962931612754
138438029120619811124579019
317841140910063118179255126
421393277641171099561251891
337614140101865116107267114
381433673110711081661151063
753439142710211170510411368
144377435721096103112694105
Fig. 15. D1=1016 D2=870
832613348852413150931612358
134478425132498623124579415
278245136218851130179259122
461352881521292287561251495
298013744892012754911812160
421397831128539019126559613
793043138510467114710261120
140413277681136103661151297
337614140105469112101811962
381433673110711081116659811
753439142310611170910063118
144377435721092107641171099
Fig.16. D1=896 D2=870
852413150872212952892012754
132498623130518821128539019
258447134278257124179255126
481332683461351693561251891
793013744812812358951412160
138438029136459415122599613
317841140510467114710261120
421393277681136103661151297
337614140105469112101811962
381433673110711081116659811
753439142310611170910063118
144377435621092107641171099
Fig. 17. D1=888 D2=870
852413150872212952911812556
132498623130518821126559217
258447134278253128199057124
481332683461352089541271693
793013744812811962971212358
138438029136459811120619415
317841140910063118139659122
421393277641171099601211495
337614140101865116107267114
381433673110711081661151063
753439142710211170510411368
144377435721096103112694105
Fig. 18. D1=992 D2=870
852413150872212952931612358
132498623130518821124579415
258447134278253128179259122
481332683461352089561251495
793013749812812754911812160
138438029136459019126559613
317841140510467114710261120
421393277681136103661151297
337614140105469112101811962
381433673110711081116659811
753439142310611170910063118
144377435721092107641171099
Fig. 19. D1=888 D2=870
872212952951412160971211962
130518821122599613120619811
238653128159457124910063118
501312089581231693641171099
852412754911812556101811566
132499019126559217116651027
258443138317841140510467114
481333079421393277681136103
832613744337614140105469112
134478029144377435721092107
278245136753439142310611170
461352881381433673110711081
Fig. 20. D1=870 D2=844
872212952971211962991011764
130518821120619811118631009
238653128139659122159465116
501312089601211495581238101
852412754911812556931611566
132499019126559217124571027
258443138311841140510467114
481333079421393277681136103
832613744337614140105469112
134478029144377435721092107
278243136753439142310611170
461352881381433673110711081
Fig.21. D1=870 D2=836

é (28) Two Tours Nearest to 'Perfection'.

Fig.22 and Fig.23 have the unique property of diagonals differing by 2 and their sum differing by 18 from twice the magic constant. That is, mod (D1- D2) = 2 and mod (D1+ D2 - 1740) = 18. Their reverse tours also have this property. This is the nearest one has approached to 'perfection'.
832613348852413150872212952
134478425132498623130518821
278245136710265116910053128
461352881661158101641172089
298013744103663118991012754
421397831114671297120619019
793043138510411962119855126
140413277681139613601211891
337614140105469112951412556
381433673110711081122599217
753439142310611170159457124
144377435721092107581231693
Fig. 22. D1=862 D2=860
832613348852413150872212952
134478425132498623130518821
278245136710265116910053128
461352881661158101641172089
793013744103663118991012754
138438029114671297120619019
317841140510411962119855126
421393277681139613601211891
337614140105469112951412556
381433673110711081122599217
753439142310611170159457124
144377435721092107581231693
Fig. 23. D1=862 D2=860

é (29) A Tour by Murray and Related Tours.

H.J.R. Murray has also given an 'almost perfect magic tour' as shown in Fig.24. Fig.25 can be derived from Murray's tour by modifying its sector F and I. Like Murray's tour, it remains 'almost perfect magic tour' if the tour begins from 73. Fig.26 and Fig.27 can also be obtained. However, Wadiar's tour is more amenable to manipulation than Murray's.
195495122215293124235091126
961212053941232251921252449
551813186452812988472612790
120974429130874627128894825
17568513235388113671138792
98119304313483343780370139
57161338439361358213772178
118994231104113403347714069
1558103114413210511273685144
1001171261106109106381417667
5914115102116211110865741436
116101601311010764914276675
Fig. 24. D1=1018 D2=870
195495122215293124235091126
961212053941232251921252449
551813186452812988472612790
120974429130874627128894825
17568513235388113631387970
98119304313483343780712139
57161338439361358213746978
118994231104113403372771401
1558103114413210511214168576
1001171261106109106387314467
5914115102116211110865142756
116101601311010764974766143
Fig. 25. D1=1018 D2=870
195495122215293124235091126
961212053941232251921252449
551813186452812988472612790
120974429130874627128894825
17568513235388113671138792
98119304313483343780370139
57161338439361358213772178
118994231104113403347714069
1558103114413210511273685144
1001176013106109106381417667
5914115102116211110865741436
116101126111010764914276675
Fig. 26. D1=1018 D2=918
195495122215293124235091126
961212053941232251921252449
551813186452812988472612790
120974429130874627128894825
17568513235388113631387970
98119304313483343780712139
57161338439361358213746978
118994231104113403372771401
1558103114413210511214168576
1001176013106109106387314467
5914115102116211110865142756
116101126111010764974766143
Fig. 27. D1=1018 D2=918

é (30) Enumeration of Magic Tours.

Enumeration of magic tours is most difficult and little progress has been made in this direction. Till now, we have enumerated about 1000 'simple magic tours', 32 'almost perfect magic tours' and 'perfect magic tours' are still to be discovered. The author estimates that their total number will be around 100000, 5000 and 10 respectively. So we have a long way to go!


Sections on this page: (26) The Raja of Mysore's Tour and Related Tours. (27) Some New 'Almost Perfect' Magic Tours. (28) Two Tours Nearest to 'Perfection'. (29) A Tour by Murray and Related Tours. (30) Enumeration of Magic Tours. Top
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Copyright G.P.Jelliss and contributing authors.