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 A130409 #4 Jul 07 2015 22:03:20 %S A130409 1,1,3,4,15,3,84,3,5,20,33,6,5460,210,12,48,255,45,1596,105,2310,1320, %T A130409 138,36,9100,546,756,112,435,30,114576,42,58905,140,105,18,767676, %U A130409 3458,16380,1680,15785,385,132440,990,434700,38640,3948,360,3248700,99450 %N A130409 Denominators of a-sequence for Sheffer matrix A130191 (Stirling2 squared). %C A130409 The numerators are found in A130408. %C A130409 See the W. Lang link in A130408. %F A130409 a(n)=denominator(r(n)),n>=0, with the rational r(n) sequence with e.g.f. x/log(1+log(1+x)). %K A130409 nonn,frac,easy %O A130409 0,3 %A A130409 _Wolfdieter Lang_ Jun 01 2007