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 A114648 #21 Feb 16 2025 08:32:59 %S A114648 0,1,10,87,834,7992,77696,758582,7436825,73129588,720726912 %N A114648 Number of occurrences of 6 as a denominator in Bernoulli(k) for 0<=k<=10^n. %H A114648 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BernoulliNumber.html">Bernoulli Number</a> %t A114648 DenominatorBernoulliBQ[n_Integer, denom_Integer] := If[EvenQ[n], Times @@ Select[Divisors[n] + 1, PrimeQ] == denom, 1 + KroneckerDelta[n, 1] == denom]; A114648[n_] := A114648[n] = Length[Select[Range[10^n], DenominatorBernoulliBQ[#, 6] &]] (* _Enrique Pérez Herrero_, Aug 01 2010 *) %Y A114648 Cf. A002445, A114649. %Y A114648 Cf. A051222, A045979. - _Enrique Pérez Herrero_, Aug 16 2010 %K A114648 nonn,hard %O A114648 0,3 %A A114648 _Eric W. Weisstein_, Dec 21 2005 %E A114648 More terms added by _Enrique Pérez Herrero_, Aug 01 2010 %E A114648 More terms from _Enrique Pérez Herrero_, Aug 16 2010 %E A114648 a(10) from _Arkadiusz Wesolowski_, Dec 02 2012