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