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 A226358 #8 Jun 05 2013 21:02:51
%S A226358 0,0,12,456,63264,33261504,68578235904,562670659193856,
%T A226358 18444482155274686464,2417777758564741377613824,
%U A226358 1267640925339738611935051382784,2658450920454274160572632643718086656,22300734564407398196216147429929635837640704
%N A226358 Number of labeled relations on {1,2,...,n} such that 1 and 2 are in the same component.
%C A226358 A062738(n) < a(n) < A002416 for n > 2.
%F A226358 E.g.f. is the double integral of A''(x)*B(x) where A(x) is the e.g.f. for A062738 and B(x) is the e.g.f. for A002416.
%e A226358 a(3) = 456 because there are 432 connected relations on [3]. Then there are 12 connected relations on [2] and for each the element 3 may be related to itself or not.
%e A226358 432 + 2*12 = 456.
%t A226358 nn=10; g=Sum[2^n^2 x^n/n!, {n, 0, nn+2}]; Join[{0,0}, Range[0,nn]! * CoefficientList[Series[D[D[Log[g],x],x]g ,{x, 0, nn}], x]]
%Y A226358 Cf. A226349, A224510.
%K A226358 nonn
%O A226358 0,3
%A A226358 _Geoffrey Critzer_, Jun 04 2013