Semi-Magic Knight's Tours

Part 3: Semi-Magic Tours of Knight on 8×N and Larger Boards

By George Jelliss, (August 2003).
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Links to related pages: IntroductionPart 1: 4 by N BoardsPart 2: 6 by N Boards


8×10 Board Some of the results given here appeared recently in The Games and Puzzles Journal, issue 26, April 2003, where some geometrical diagrams of the tours also appear.

I have constructed nine 8×10 tours (three typical examples shown here) based on extending the braid in the Beverley type tours on the 8×8 to cover the extra two files. They all add to 324 in the files, as required in a magic tour, but the ranks sum to two alternating values. The first has the sums 365 and 445, the second 395 and 415, the third 393 and 417.

 1 38 59 64  5 36 55 66  7 34
60 63  2 37 56 65  6 35 54 67
39 58 61  4 31 10 69 52 33  8
62  3 40 57 70 51 32  9 68 53
41 78 19 24 11 30 49 72 13 28
20 23 42 77 50 71 12 29 48 73
79 18 21 44 25 16 75 46 27 14
22 43 80 17 76 45 26 15 74 47
 1 38 59 64  5 66  7 34 53 68
60 63  2 37 56 35 54 67 32  9
39 58 61  4 65  6 33  8 69 52
62  3 40 57 36 55 70 51 10 31
41 78 19 24 45 26 11 30 71 50
20 23 42 77 16 75 48 73 12 29
79 18 21 44 25 46 27 14 49 72
22 43 80 17 76 15 74 47 28 13
 1 38 59 64  5 66  7 68 53 32
60 63  2 37 56 35 54 33  8 69
39 58 61  4 65  6 67 10 31 52
62  3 40 57 36 55 34 51 70  9
41 78 19 24 45 26 47 30 11 72
20 23 42 77 16 75 14 71 50 29
79 18 21 44 25 46 27 48 73 12
22 43 80 17 76 15 74 13 28 49
65 70 67 60 63 18 21 14 11 16
68 57 64 19 22 59 62 17 24 13
71 66 69 58 61 20 23 12 15 10
56 29  6 73 54 27  8 75 52 25
 5 72 55 28  7 74 53 26  9 76
30 35 32  3 38 41 80 49 46 51
33  4 37 42 79  2 39 44 77 48
36 31 34  1 40 43 78 47 50 45

The fourth example above is constructed by the ‘lozenge’ method that I found for 12×12 magic tours, but due to the limitations of this board the result is only quasi-magic. The 10-cell lines add to 405 (consisting mainly of pairs adding to 81). The 8-cell lines add to 364 and 284 (the magic constant would be 324).

8×14 Board No results to hand.

8×18 Board These two new examples were constructed by splitting the 8×8 magic tour 00b in two and joining up the loose ends by four paths in direct qaternary symmetry.

 42  31 110 107  26  47 128  87  24  85  22  53 134  83  74   7  66 143
111 108  43  30 129  88  25  48 127  54 133  84  21  52  65 142  75   6
 32  41 106 109  46  27 130  55  86  23 126  51  62 135   8  73 144  67
105 112  29  44 117 100  89  14  49 132  95  20   9  64 141  68   5  76
 40  33 116 101  28  45  56 131  96  13  50 125 136  81  72  77 140   1
113 104  39  36  99 118  15  90  59 122  19  94  63  10 137   4  69  78
 34  37 102 115  16  57 120  97  18  91  12  61 124  93  80  71   2 139
103 114  35  38 119  98  17  58 121  60 123  92  11  62   3 138  79  70
 42  31 110 107  26  53  98 123 126  55  58  11 128  83  74   7  66 143
111 108  43  30  99 124  25  54  97  12 127  84  57  10  65 142  75   6
 32  41 106 109  52  27  96 125 122  59  56  13  82 129   8  73 144  67
105 112  29  44 117 100  51  24  95  14  85 130   9  64 141  68   5  76
 40  33 116 101  28  45  94 121  50 131  60  15 136  81  72  77 140   1
113 104  39  36  93 118  49  20  23  86  89 132  63  16 137   4  69  78
 34  37 102 115  46  21 120  91  48 133  18  61  88 135  80  71   2 139
103 114  35  38 119  92  47  22  19  90  87 134  17  62   3 138  79  70

10×10 Board.

Here is Tom Marlow's 10×10 semi-magic tour with quaternary symmetry (i.e. 90 degree rotational symmetry) which appeared in The Games and Puzzles Journal, issue 25, March 2003, where a geometrical diagram is also given. The yellow coloured squares are those containing numbers of the forms 4n + 2 or 4n + 3: there must be an even number of these in a line for it to be magic.

77 58 45 56 41 60 47 50 19 52
44 73 76 59 46 55 18 53 48 33
75 78 57 42 61 40 49 32 51 20
72 43 74 79 64 37 54 17 34 31
85 80 65 62 13 88 39 36 21 16
66 71 86 89 38 63 12 15 30 35
81 84 67 4 87 14 29 24 93 22
70 1 82 99 90 11 92 7 28 25
83 98 3 68 5 96 9 26 23 94
2 69 100 97 10 91 6 95 8 27


Back to: KTN Index Page.

Links to related pages: IntroductionPart 1: 4 by N BoardsPart 2: 6 by N Boards