A magic square is a square of numbers in which all rows, all columns and both diagonals add to the same number, or magic total. The simplest magic square using distinct numbers is this:
6 1 8
7 5 3
2 9 4
It’s easy to prove that the magic total of a 3×3 magic square must be three times the central number. Accordingly, if the central number is 37, the magic total must be 111. There are lots of ways to create a magic square with 37 at its heart, but this is my favourite:
43 | 01 | 67
61 | 37 | 13
07 | 73 | 31
The square is special because all the numbers are prime, or divisible by only themselves and 1 (though 1 itself is not usually defined as prime in modern mathematics). I like the 37-square even more now that I’ve discovered it can be found inside another all-prime magic square:
0619 = 0006[37] | 0097 = 00000010 | 1123 = [11][56]
1117 = [11][50] | 0613 = 0006[31] | 0109 = 0001[12]
0103 = 00000016 | 1129 = [11][62] | 0607 = 0006[25]
Magic total = 1839
The square is shown in both base-10 and base-97. If the digit-sums of the base-97 square are calculated, this is the result (e.g., the digit-sum of 6[37][b=97] = 6 + 37 = 43):
43 | 01 | 67
61 | 37 | 13
07 | 73 | 31
This makes me wonder whether the 613-square might nest in another all-prime square, and so on, perhaps ad infinitum [Update: yes, the 613-square is a nestling]. There are certainly many nested all-prime squares. Here is square-631 in base-187:
661 = 003[100] | 379 = 00000025 | 853 = 004[105]
823 = 004[075] | 631 = 003[070] | 439 = 002[065]
409 = 002[035] | 883 = 004[135] | 601 = 003[040]
Magic total = 1893
Digit-sums:
103 | 007 | 109
079 | 073 | 067
037 | 139 | 043
Magic total = 219
There are also all-prime magic squares that have two kinds of nestlings inside them: digit-sum magic squares and digit-product magic squares. The digit-product of a number is calculated by multiplying its digits (except 0): digit-product(37) = 3 x 7 = 21, digit-product(103) = 1 x 3 = 3, and so on. In base-331, this all-prime magic square yields both a digit-sum square and a digit-product square:
503 = 1[172] | 359 = 1[028] | 521 = 1[190]
479 = 1[148] | 461 = 1[130] | 443 = 1[112]
401 = 1[070] | 563 = 1[232] | 419 = 1[088]
Magic total = 1383
Digit-sums:
173 | 029 | 191
149 | 131 | 113
071 | 233 | 089
Magic total = 393
Digit-products:
172 | 028 | 190
148 | 130 | 112
070 | 232 | 088
Magic total = 390
Here are two more twin-bearing all-prime magic squares:
Square-719 in base-451:
761 = 1[310] | 557 = 1[106] | 839 = 1[388]
797 = 1[346] | 719 = 1[268] | 641 = 1[190]
599 = 1[148] | 881 = 1[430] | 677 = 1[226]
Magic total = 2157
Digit-sums:
311 | 107 | 389
347 | 269 | 191
149 | 431 | 227
Magic total = 807
Digit-products:
310 | 106 | 388
346 | 268 | 190
148 | 430 | 226
Magic total = 804
Square-853 in base-344:
883 = 2[195] | 709 = 2[021] | 967 = 2[279]
937 = 2[249] | 853 = 2[165] | 769 = 2[081]
739 = 2[051] | 997 = 2[309] | 823 = 2[135]
Magic total = 2559
Digit-sums:
197 | 023 | 281
251 | 167 | 083
053 | 311 | 137
Magic total = 501
Digit-products:
390 | 042 | 558
498 | 330 | 162
102 | 618 | 270
Magic total = 990
Proviously Post-Posted (please peruse):
• More Multi-Magic