A176274 -id:A176274 - cp's OEIS frontend

A176275 Numbers of the form 6k+1 with the least prime divisor of the form 6m-1.

25, 55, 85, 115, 121, 145, 175, 187, 205, 235, 253, 265, 289, 295, 319, 325, 355, 385, 391, 415, 445, 451, 475, 493, 505, 517, 529, 535, 565, 583, 595, 625, 649, 655, 667, 685, 697, 715, 745, 775, 781, 799, 805, 835, 841, 865, 895, 901, 913, 925, 943, 955, 979, 985, 1003, 1015, 1045, 1075

Offset: 1

Vladimir Shevelev, Apr 14 2010

nonn

All terms of A108166 are in the sequence.

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Cf. A176274, A176262, A176256, A176257, A176258, A176255, A108166, A016969, A007528.

Select[6*Range[200] + 1, IntegerQ[(FactorInteger[#][[1, 1]] + 1)/6] &] (* Harvey P. Dale, Sep 19 2018 *)

isok(n) = ((n % 6) == 1) && (n != 1) && ((vecmin(factor(n)[,1]) % 6) == 5); \\ Michel Marcus, Feb 08 2016

Corrected by R. J. Mathar, May 03 2013

A176278 Numbers of the form 6k-1 with the least prime divisor of the form 6m+1.

Original entry on oeis.org

77, 119, 161, 203, 221, 287, 299, 329, 371, 377, 413, 437, 497, 533, 539, 551, 581, 611, 623, 689, 707, 749, 767, 779, 791, 833, 893, 917, 923, 959, 1001, 1007, 1043, 1079, 1121, 1127, 1157, 1169, 1211, 1253, 1271, 1313, 1337, 1349, 1379, 1391, 1421, 1457

Offset: 1

Vladimir Shevelev, Apr 14 2010

nonn

By definition, all terms are composite numbers.

Amiram Eldar, Table of n, a(n) for n = 1..10000

Cf. A176275, A176274, A176262, A176258, A176257, A176256, A176255, A108166, A016969, A007528.

Select[Range[11,2581,6],1==Mod[FactorInteger[ # ][[1,1]],6]&] (* Zak Seidov, Apr 14 2010 *)

isok(n) = ((n % 6) == 5) && ((vecmin(factor(n)[,1]) % 6) == 1); \\ Michel Marcus, Feb 08 2016

Corrected (erroneous 341 deleted) and extended by Zak Seidov, Apr 14 2010

cp's OEIS Frontend

A176275 Numbers of the form 6k+1 with the least prime divisor of the form 6m-1.

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