New Method for Loubère, Méziriac and Méziriac Type Magic Squares (Part IV)

Rules for Construction

A stairs

Loubère and Méziriac Squares-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...

Equality of squares of Parts (IA and IB) and Part IV

The squares in this section were found to be equivalent to those in Parts (IA and IB). Rotation of the squares in this section 180o degrees about the main diagonal gave squares identical to those in Parts (IA and IB). The 11×11 squares at the end of this section, however, are an addition to those shown in Parts (IA and IB).

The Loubère, Méziriac and Méziriac type Squares

The 5×5 regular Loubère (AG on the left) and the Méziriac (AH on the right) squares are shown below . The 7×7 (AI) and 9×9 (AJ) Méziriac squares are also shown:

AG (4↑1↓)
17 24 1 8 15
23 5 7 14 16
4613 20 22
10 12 19 21 3
11 18 25 2 9
AH (2↑3↓)
23 6 19 2 15
10181 14 22
17513 21 9
41225 8 16
11 24 7 20 3
AI (2↑5↓)
46 15 40 9 343 28
21 39 8 33 227 45
38 14 32 1 2644 20
1331725 43 1937
30 6 24 49 1836 12
5 23 48 17 4211 29
22 47 16 41 1035 4
AJ (2↑7↓)
77 28 692061 12 534 45
36 68 196011 52 344 76
67 27 591051 2 4375 35
26 58 18501 42 7434 66
571749941 73 336525
16 48 84081 32 6424 56
47 7 398031 72 2355 15
6 38 793071 22 6314 46
37 78 297021 62 1354 5

Both the Méziriac and the Loubère are magic for every odd number n. In addition, all three Méziriac squares (AH), (AI) and (AK) use a shift of two cells up or a complementary shift of 3, 5 or 7 down, respectively. These squares are what are known as the regular Méziriac, though the digit 1 is positioned over the central cell instead of to the right as it is normally published. Both sites are equivalent, however.

As was shown in Part IA a table was generated for right cell shifts. For these squares, however, since the digit 1 is placed to the north of central cell C the shifts are the same but in the upward direction as in the following table :

Up Cell Shifts
C246810 121416182022242628... N ↑

Note that the first entry, 2, corresponds to a Méziriac and the last cell entry to a Loubère (depending on what n is) while all other entries between these two to Méziriac types.

Moreover, the partial table above (since the table is ∞) has the following characteristics: those n that are divisible by three 6,12,18; those by five 10, 20; and those by seven 14, 28 cannot be constructed. Construction of the other two 7×7 squares (AK) and (AL) are both are shown below. Besides the Loubère (AL) the Méziriac type (AK) is also magic.

AK (4↑ 3↓)
13 47 32 17 236 28
46 31 16 1 4227 12
30 15 7 41 2611 45
2164025 10 4429
5 39 24 9 4335 20
38 23 8 49 3419 4
22 14 48 33 183 37
AL (6↑ 1↓)
30 39 48 1 1019 28
38 47 7 9 1827 29
46 6 8 17 2635 37
5141625 34 3645
13 15 24 33 4244 4
21 23 32 41 433 12
22 31 4049 2 1120

The results for the 9×9, where n is composite, are identical to Part IA. (AM), a 4 up shift, as well as the 6 up shift square (not shown) are the only two squares that are not magic:

9×9
C246 8N ↑
AM (4↑ 5↓)
57 78 183051 72 324 45
77 17 295071 2 2344 56
16 28 49701 22 4355 76
36 48 69921 42 6375 15
476882041 62 741435
67 7 194061 73 1334 46
6 27 396081 12 3354 66
26 38 598011 32 5365 5
37 58 791031 52 644 25

In addition, other squares with composite n may or may not contain viable magic squares. It was found (by actual construction) that three magic squares were possible for the 15×15 types, two for the 21×21 types and eight for the 25×25 types (shown below in the shift cell table). Moreover, the cell shift tables below plus the 9×9 above appear to show a particular symmetrical cell pattern [(1,1), (1,1,1), (1,1) and (2,1,2,1,2)]. Note that all those in white are either non magic or inconstructible:

15×15
C246 8101214 N ↑
21×21
C246 8101214161820 N ↑
25×25
C246 81012 14161820 2224 N ↑

The rule for forming these squares are as follows:

(a) Construct the cell shift table for each square
(b) Divide the numbers into symmetry pairs
(c) Cross out those numbers that are divisible by the composite parts
(d) By symmetry match up that crossed out values with uncrossed ones
(e) Cross out the matched number
(f) By symmetry match the uncrossed value with uncrossed ones

The uncrossed values remaining should be relatively prime to the prime numbers of the composite numbers, i.e., they are not divisible by the composite primes only by the number one. The uncrossed numbers in white are those squares which are magic. Confirmation via actual construction confirms the rule. In this case the rules were developed after the construction. Thus, once we have the rules it's easy to determine which squares are magic without having to go thru the actual construction.

Below is an example using and n order of 25:

I
C246 81012 14161820 2224 N ↑
II
C246 81012 14161820 2224 N ↑
III
C246 81012 14161820 2224 N ↑

So by symmetry there are four values to the left of the symmetry plane and four to the right.

(AN) and (AO) two out of the other five possible prime squares of 11×11, both of which are magic, are depicted below. The other square in the set (K) shown in Part IB was presented but with a 180o degree rotation about the main diagonal.

AN (4↑ 7↓)
31 117 824712 109 7439 490 66
116 81 4622108 73 383 8965 30
80 45 2110772 37 299 6429 115
55 20 1067136 1 9863 28114 79
19 105 703511 97 6227 11378 54
1046934109661 261128853 18
68 44 99560 25 11187 5217 103
43 8 945924 121 8651 16102 67
7 93 5823120 85 5015 10177 42
92 57 3311984 49 14100 7641 6
56 32 1188348 13 11075 405 91
AO (8↑ 3↓)
104 32 7011936 85 251 8917 66
31 69 1183584 1 5099 1665 103
68 117 348311 49 9815 64102 30
116 44 821048 97 1463 10129 67
43 81 94796 13 62100 2877 115
80846951261 1102776114 42
7 45 942260 109 2675 11341 79
55 93 2159108 25 74112 4078 6
92 20 5810724 73 11139 885 54
19 57 1062372 121 3887 453 91
56 105 3371120 37 863 5290 18

To finish off this discussion: below is the 15×15 square (NM) with the digit 1 in position two cells north of the central cell, thus requiring a four cell shift available from the shift cell table. This square, though constructible, is non magic (first and second row do not sum to 1695).

NM (4↑ 11↓)
57 219 1569345207 144 81 18195 13269 6168 120
218 155 9244206143 80 17 194131 685 16711956
154 91 4320514279 16 193130 674166 11855217
105 42 2041417830 192 129 663 180117 54216 153
41 203 1407729191 128 65 2179 11653 215152 104
202 139 7628190127 64 1 178115 52214 151103 40
138 90 2718912663 15 177 11451 213165 10239 201
89261881256214176113 50212 164101 38200 137
25 187 1246113175 112 49 211163 10037 199136 88
186 123 7512174111 48 225 16299 36198 15087 24
122 74 1117311047 224 161 9835 197149 8623 185
73 10 17210946223 160 97 34196 14885 22184 121
9 171 10860222159 96 33 210147 8421 183135 72
170 107 5922115895 32 209 14683 20182 13471 8
106 58 2201579431 208 145 8219 181133 707 169

This completes this section (Part IV). To return to Part III To return to homepage.


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