A067778 Numbers k such that gcd(k, numerator(B(2*k))) is not squarefree where B(2*k) are the Bernoulli numbers.

25, 49, 75, 98, 121, 125, 169, 175, 196, 225, 242, 245, 275, 289, 325, 338, 343, 361, 363, 375, 392, 425, 475, 484, 490, 507, 525, 529, 539, 575, 578, 625, 637, 675, 676, 686, 722, 725, 726, 775, 784, 825, 833, 841, 845, 847, 867, 875, 925, 931, 961, 968

Offset: 1

Author

Benoit Cloitre, Feb 06 2002

Keywords

• nonn

Comments

All members so far are themselves not squarefree. - Robert G. Wilson v, Aug 28 2004

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A013929, A027641, A027642, A097704.

Programs

Mathematica

Select[ Range[1000], !SquareFreeQ[ GCD[ #, Numerator[ BernoulliB[2# ]] ]] &] (* Robert G. Wilson v, Aug 28 2004 *)

Extensions

More terms from Robert G. Wilson v, Aug 28 2004