A189188 -id:A189188 - cp's OEIS frontend

A191679 Potential magic constants of 9 X 9 magic squares composed of consecutive primes.

2211, 2261, 2311, 2463, 2725, 4257, 6125, 6611, 7821, 9841, 9973, 10303, 10499, 10631, 10953, 11987, 12115, 12179, 12243, 12309, 12375, 12637, 12837, 13497, 13695, 14169, 15063, 15395, 16207, 16483, 16821, 17605, 17891, 19017, 20345, 20487, 21135, 22539, 22811, 23219, 23985

Offset: 1

Natalia Makarova, Jun 11 2011

nonn

For a 9 X 9 magic square composed of 81 consecutive primes, it is necessary that the sum of these primes is a multiple of 9.

This sequence consists of integers equal the sum of 81 consecutive primes divides by 9. It is not known whether each such set of consecutive primes can be arranged into 9 X 9 magic square but it looks plausible.

			a(1)=2211 for a square containing prime(12)..prime(92):
  [37 127 163 179 229 233 379 421 443
   41 431 463 457  59 139 433 109  79
  409 311 389  71 307 347 281  53  43
  373 137 181 251 401 239 317  89 223
  173 419 101 103 113 353 313 277 359
   97 383 397 479  47 197 107 263 241
  349 131 193 149 367 199  73 467 283
  439  61 257 191 227 167 151 449 269
  293 211  67 331 461 337 157  83 271]
a(2)=2261 for a square containing prime(13)..prime(93):
  [41  379  281  467  349  257  229  199   59
  313  223  127  337  131  101  479  107  443
  409   71  331   79  137  263  347  271  353
  211  307  487  149  251  293  181  113  269
  191  419  109  439  173  233  103  397  197
   97  283  193  317  433  457  241  157   83
  461  139  239  359  373  179   67  401   43
   89  277   73   53  367  167  463  389  383
  449  163  421   61   47  311  151  227  431]

Stefano Tognon, Squares from 37 (in Italian).
Natalia Makarova, Sequence of Magic Numbers MK 9th Order (in Russian).

Cf. A073520, A173981, A176571, A177434, A188536, A189188.

s:= proc(n) option remember;
       `if` (n=1, add (ithprime(i), i=1..81),
                  ithprime(n+80) -ithprime(n-1) +s(n-1))
    end:
a:= proc(n) option remember; local k, m;
       a(n-1);
       for k from 1+b(n-1) while irem (s(k), 9, 'm')<>0 do od;
       b(n):= k; m
    end:
a(0):=0: b(0):=0:
seq (a(n), n=1..50);

Total[#]/9&/@Select[Partition[Prime[Range[500]],81,1],Divisible[ Total[ #],9]&] (* Harvey P. Dale, Jan 08 2014 *)

Edited by Max Alekseyev, Jun 18 2011

A192087 Potential magic constants of a 10 X 10 magic square composed of consecutive primes.

Original entry on oeis.org

2862, 3092, 3500, 4222, 4780, 5608, 7124, 10126, 10198, 11212, 11426, 12140, 12212, 12284, 12356, 12428, 12714, 12854, 12924, 15270, 16252, 16476, 18594, 18672, 18750, 18828, 19214, 20764, 21150, 23752, 24214, 24598, 24828, 27180, 27342, 27424, 27916, 28666, 29406, 29568

Offset: 1

Natalia Makarova, Jun 23 2011

nonn

For a 10 X 10 magic square composed of 100 consecutive primes, the sum of these primes must be a multiple of 20.
This sequence consists of even integers equal the sum of 100 consecutive primes divided by 10. It is not known whether each such set of consecutive primes can be arranged into a 10 X 10 magic square but it looks plausible.
Actual magic squares were constructed for all listed magic constants <= 11212.

			a(1)=2862 for a square containing prime(9)..prime(108):
  [23  179  409  373  263  137  461  457  523   37
  193  353  443  199  317  109  337  397  131  383
   71   73  389  251  593  167  439  449  233  197
  571  293  101  229   29  557  271   31  379  401
  127  419  283  241  269  239  547   89  181  467
  491  433  223  113   41  577   43  311  563   67
  281   97  163  587  191  313  149  509  421  151
  307  499  227  431  103   83   59  479  211  463
  277  359  257  331  569  541   53   79   47  349
  521  157  367  107  487  139  503   61  173  347]
.
a(10)=11212
  [769   863  1171   967   859  1381  1237  1459  1289  1217
  1163   953   797  1297  1049  1021  1303   977  1423  1229
   809  1277  1153   937  1151  1409  1291   839  1249  1097
  1429  1231  1193  1451  1061   829   821  1361   823  1013
  1453   997   947  1091  1321   887  1283   941   811  1481
  1069  1201  1427  1129   907   919  1373  1039  1117  1031
  1009  1123  1301  1093  1367  1483   911  1051  1087   787
   991  1109  1279   877  1223   929  1187  1433  1327   857
  1213  1439  1063   971  1447   883   773  1259   983  1181
  1307  1019   881  1399   827  1471  1033   853  1103  1319]

Natalia Makarova, Sequence of Magic Numbers MK 10th Order (in Russian).

Cf. A073520, A173981, A176571, A177434, A188536, A189188, A191679.

s:= proc(n) option remember;
       `if` (n=1, add (ithprime(i), i=1..100),
                  ithprime(n+99) -ithprime(n-1) +s(n-1))
    end:
a:= proc(n) option remember; local k, m;
       a(n-1);
       for k from 1+b(n-1) while irem (s(k), 20, 'm')<>0 do od;
       b(n):= k; m
    end:
a(0):=0: b(0):=0:
seq (2*a(n), n=1..50);

cp's OEIS Frontend

A191679 Potential magic constants of 9 X 9 magic squares composed of consecutive primes.

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