New Method and Rules for Loubère Type Squares (Part II)

A stairs

Loubère Square Background

The Siamese method which includes both the Loubère and Méziriac magic squares have the property that the center cell must always contain the middle number of the series of numbers used, i.e. a number which is equal to one half the sum of the first and last numbers of the series, or ½(n2 + 1). In addition, the sum of the horizontal rows, vertical columns and corner diagonals are equal to the magic sum S. Both squares also require an upward stepwise addition of consecutive numbers, i.e., 1,2,3... It's also a fact that only one Loubère square per order n has been handed down thru the centuries. In addition, construction of the square requires a one down shift after filling of a diagonal to move to the next diagonal until the square is filled.

Loubère Type Squares of Order 15

This page is a continuation of Part I which contains the rules for construction of these Loubère type squares.

The K shift table for the 15th order squares are listed below. Only three squares can be produced from these K values, the 4, 6 and the 1, the latter corresponding to the regular Loubère square. Since we know the Loubère is magic only those squares with the initial number 1 at the second and fourteenth positions will be constructed since all other squares with K values in green are either non magic or inconstructible. Again the K table is a table of knight moves for the square whose initial starting number 1 is place at position ½K in the square being constructed.

The K shift table is constructed out of two complementary strands connected at the hinge where the hinge is the regular Loubère square. Moreover, the table is divided into complementary pairs which are used to produce some white (magic) and some green (inconstructible or non magic constructible) squares. To use the table below, one first crosses out the K values which are divisible by 3 or 5 followed by crossing out their complements. Any K values not crossed out (in white) lead to the formation of magic squares. These non crossed values are relatively prime to the order n whether that order is prime or a product of primes. Note that K knight moves of 12 and 5, a complementary pair, result in inconstructible squares.

15×15 K moves
246 81012 14
1
151311 975 3

The first 15th order square is the D4 below with the starting 1 at row 1 cell 2 of the 15×15 square. The headings above row one of the squares are explained in Part I:

D4 (4→ 13←)
24681012141 3579111315
173 1 6912219018 86 139 20735 103156 22452 120
15 68 1211891785 138 206 34102 155223 51119172
67 135 1881684137 205 33101 15422250 11817114
134 187 3083136204 32 100 153221 49117 17013 66
186 29 8215020331 99 152 22048 116169 1265 133
28 81 1492024598 151 219 47115 16811 64132 185
80 148 2014497165 218 46 114167 1063 131184 27
147200439616421760113 1669 62130 18326 79
199 42 9516321659 112 180 861 129182 2578 146
41 94 16221558111 179 7 75128 18124 77145 198
93 161 21457110178 6 74 127195 2376 144197 40
160 213 561091775 73 126 19422 90143 19639 92
212 55 108176472 125 193 2189 142210 3891 159
54 107 175371124 192 20 88141 20937 105158 211
106 174 270123191 19 87 140208 36104 157225 53

The second 15th order square is the D13 below with the starting 1 at row 1 cell 14 of the 15×15 square:

D13 (13→ 4←)
24681012141 3579111315
224 103 2078619069 173 52 15635 13918 1221 120
102 206 8518968172 51 155 34138 17121 15119223
205 84 1886717150 154 33137 1613514 118222101
83 187 6617049153 32 136 30134 13117 221100 204
186 65 1694815231 150 29 13312 116220 99203 82
64 168 4715145149 28 132 11115 21998 20281 185
167 46 1654414827 131 10 114218 97201 80184 63
6016443147261309113 21796 20079 18362 166
163 42 146251298 112 216 95199 78182 61180 59
41 145 241287111 215 94 19877 18175 17958 162
144 23 1276110214 93 197 76195 74178 57161 40
22 126 510921392 196 90 19473 17756 16039 143
125 4 1082129121089193 72 176 55 1593814221
3 107 21110520988 192 71 17554 15837 14120 124
106 225 10420887191 70 174 53157 36140 19123 2

Two 11th Order Squares

The next two squares are 11th order and are complementary to each other. The E8 and E5 have right and left knight moves opposite to one another as seen in the caption above the square. From the K shift table it can be seen that nine of the squares that are generated from these K values are constructible and magic.

11×11 K moves
246 810
1
11 975 3
E8 (8→ 5←)
2468101 357911
14 94 53181 40 12068 27107 66
93 52 118039 119 6726 10665 13
51 10 7938118 77 25105 6412 92
9 78 3711776 24 10463 2291 50
88 36 1167523 103 6221 9049 8
35115743310261 2089487 87
114 73 3210160 19 9947 686 34
72 31 1005918 98 465 8544 13
30 110 581797 45 484 43112 71
109 57 169655 3 8342 11170 29
56 15 95542 82 41121 6928 108
E5 (5→ 8←)
2468101 357911
40 14 1209468 53 271 10781 66
13 119 936752 26 11106 8065 39
118 92 775125 10 10579 6438 12
91 76 50249 104 7863 3722 117
75 49 238103 88 6236 21116 90
483371028761 352011589 74
32 6 1018660 34 19114 9973 47
5 100 855944 18 11398 7246 31
110 84 584317 112 9771 4530 4
83 57 4216111 96 7055 293 109
56 41 1512195 69 5428 2108 82

This completes this section (Part II). To return to Part I or to return to homepage.


Copyright © 2020 by Eddie N Gutierrez. E-Mail: enaguti1949@gmail.com