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

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

Author

Vladimir Shevelev, Apr 14 2010

Keywords

• nonn

Comments

By definition, all terms are composite numbers.

Links

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

Crossrefs

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

Programs

Mathematica

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

PARI

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

Extensions

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