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

Author

Vladimir Shevelev, Apr 14 2010

Keywords

• nonn

Comments

All terms of A108166 are in the sequence.

Links

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

Crossrefs

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

Programs

Mathematica

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

PARI

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

Extensions

Corrected by R. J. Mathar, May 03 2013