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 A260950 #10 Aug 05 2015 04:10:09 %S A260950 1,-2,1,1,-10,-61,-382,-3489,-39001,-484075,-6619449,-99610098, %T A260950 -1638687448,-29255834780,-563343011377,-11639759292186, %U A260950 -256916737692132,-6034068201092777,-150271333127027481,-3955735249215111270,-109757859467421502791 %N A260950 Coefficients in asymptotic expansion of sequence A259872. %H A260950 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 A260950 a(k) ~ -2 * exp(-1) * (k-1)! / (log(2))^k. %e A260950 A259872(n)/((n-1)!/exp(1)) ~ 1 - 2/n + 1/n^2 + 1/n^3 - 10/n^4 - 61/n^5 - ... %t A260950 nmax = 25; b = CoefficientList[Assuming[Element[x, Reals], Series[x/(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 A260950 Cf. A259872, A260578, A260948, A260949. %K A260950 sign %O A260950 0,2 %A A260950 _Vaclav Kotesovec_, Aug 05 2015