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 A260949 #10 Aug 05 2015 04:09:55
%S A260949 1,4,16,76,416,2576,17840,137268,1170104,11050940,115885968,
%T A260949 1353366864,17640817784,256630492660,4153220868128,74315436120300,
%U A260949 1458541231513152,31131651836906752,716862465409883040,17683184383300077828,464519709712796199816
%N A260949 Coefficients in asymptotic expansion of sequence A259871.
%H A260949 Richard J. Martin, and Michael J. Kearney, <a href="http://dx.doi.org/10.1007/s00493-014-3183-3">Integral representation of certain combinatorial recurrences</a>, Combinatorica: 35:3 (2015), 309-315.
%F A260949 a(k) ~ 4 * exp(-1) * (k-1)! / (log(2))^k.
%e A260949 A259871(n)/((n-1)!/exp(1)) ~ 1 + 4/n + 16/n^2 + 76/n^3 + 416/n^4 + 2576/n^5 + ...
%t A260949 nmax = 25; b = CoefficientList[Assuming[Element[x, Reals], Series[x/(2*ExpIntegralEi[1 + 1/x]/Exp[1 + 1/x] - 1)^2, {x, 0, nmax+1}]], x]; Table[Sum[b[[k+1]]*StirlingS2[n, k-1], {k, 1, n+1}], {n, 0, nmax}]
%Y A260949 Cf. A259871, A260578, A260948, A260950.
%K A260949 nonn
%O A260949 0,2
%A A260949 _Vaclav Kotesovec_, Aug 05 2015