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 A174276 #7 Aug 09 2012 06:24:25
%S A174276 1,2,6,30,70,210,2310,10010,6006,510510,461890,9699690,31870410,
%T A174276 74364290,223092870,6469693230,6077590610,200560490130,200560490130,
%U A174276 494715875654,674612557710,60850052705442,872184088778002,13082761331670030
%N A174276 Denominator of the n-th term of the inverse binomial transform of 1, 1/2, B_4, B_6, B_8,..., a modified Bernoulli sequence.
%C A174276 The numerators are in A174289. The input sequence starts 1, 1/2, 1/6, -1/30, 1/42....
%C A174276 The inverse binomial transform generates 1, -1/2, 1/6, -1/30, 11/70, -137/210, 4157/2310,...
%p A174276 read("transforms") ; L := [1,1/2,seq(bernoulli(2*i),i=1..30)] ; BINOMIALi(L) ; apply(denom,%) ;
%t A174276 b[0]=1; b[1]=1/2; b[n_] := BernoulliB[2n-2]; a[n_] := Sum[(-1)^(n-k)*Binomial[n, k]*b[k], {k, 0, n}]; Table[a[n], {n, 0, 23}] // Denominator (* Jean-François Alcover_, Aug 09 2012 *)
%Y A174276 Cf. A000367, A164555, A006954.
%K A174276 nonn,frac
%O A174276 0,2
%A A174276 _Paul Curtz_, Mar 14 2010