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 A261253 #10 Aug 12 2015 16:12:31
%S A261253 1,-4,2,-2,-31,-288,-2939,-33944,-438614,-6266312,-98050303,
%T A261253 -1667563622,-30631857759,-604518210964,-12758658946466,
%U A261253 -286833669370926,-6844757550430019,-172833310268551740,-4604828067485736507,-129123684195177403168,-3801830662346341617586
%N A261253 Coefficients in an asymptotic expansion of sequence A261239.
%H A261253 Vaclav Kotesovec, <a href="/A261253/b261253.txt">Table of n, a(n) for n = 0..400</a>
%F A261253 a(k) ~ -k! / (log(2))^(k+1).
%F A261253 For n>0, a(n) = Sum_{k=1..n} A261254(k) * Stirling2(n-1, k-1).
%e A261253 A261239(n)/(-3*n!) ~ 1 - 4/n + 2/n^2 - 2/n^3 - 31/n^4 - 288/n^5 - 2939/n^6 - ...
%t A261253 Flatten[{1, Table[Sum[CoefficientList[Assuming[Element[x, Reals], Series[E^(4/x)*x^4/ExpIntegralEi[1/x]^4, {x, 0, 25}]], x][[k+1]] * StirlingS2[n-1, k-1], {k, 1, n}], {n, 1, 25}]}]
%Y A261253 Cf. A003319, A260503, A259472, A261214, A261239, A261254.
%K A261253 sign
%O A261253 0,2
%A A261253 _Vaclav Kotesovec_, Aug 12 2015