%I #33 Aug 31 2024 04:32:37
%S 25,49,75,98,121,125,169,175,196,225,242,245,275,289,325,338,343,361,
%T 363,375,392,425,475,484,490,507,525,529,539,575,578,625,637,675,676,
%U 686,722,725,726,775,784,825,833,841,845,847,867,875,925,931,961,968
%N Numbers k such that gcd(k, numerator(B(2*k))) is not squarefree where B(2*k) are the Bernoulli numbers.
%C All members so far are themselves not squarefree. - _Robert G. Wilson v_, Aug 28 2004
%H Amiram Eldar, <a href="/A067778/b067778.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[ Range[1000], !SquareFreeQ[ GCD[ #, Numerator[ BernoulliB[2# ]] ]] &] (* _Robert G. Wilson v_, Aug 28 2004 *)
%Y Cf. A013929, A027641, A027642, A097704.
%K nonn
%O 1,1
%A _Benoit Cloitre_, Feb 06 2002
%E More terms from _Robert G. Wilson v_, Aug 28 2004