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 A009198 #20 May 13 2022 12:45:05
%S A009198 1,1,-2,0,18,-85,155,1057,-13636,86361,-271783,-1518539,35743378,
%T A009198 -376883351,2663534939,-8383983593,-117620643336,2907896789457,
%U A009198 -39364767602331,389671721253889,-2504052803057234,-3842812946739679,465976686530941599
%N A009198 E.g.f. exp(log(1+x)/exp(x)).
%C A009198 For n>=40 the +- signs alternate regularly. - _Vaclav Kotesovec_, May 13 2022
%H A009198 Vaclav Kotesovec, <a href="/A009198/b009198.txt">Table of n, a(n) for n = 0..450</a>
%F A009198 a(n)=sum(k=1..n, sum(i=k..n, binomial(n,i)*(stirling1(i,k)*k^(n-i)*(-1)^(n-i)))), n > 0, a(0)=1. - _Vladimir Kruchinin_, Jun 29 2011
%F A009198 a(n) ~ n! * (-1)^n / (Gamma(-exp(1)) * n^(1+exp(1))) * (1 - (exp(2) + exp(1)) * log(n)/n). - _Vaclav Kotesovec_, May 13 2022
%t A009198 nmax = 20; CoefficientList[Series[E^(Log[1+x]/E^x), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, May 13 2022 *)
%o A009198 (Maxima)
%o A009198 a(n):=if n=0 then 1 else sum(sum(binomial(n,i)*(stirling1(i,k)*k^(n-i)*(-1)^(n-i)),i,k,n),k,1,n); /* _Vladimir Kruchinin_, Jun 29 2011 */
%K A009198 sign,easy
%O A009198 0,3
%A A009198 _R. H. Hardin_
%E A009198 Extended with signs by _Olivier Gérard_, Mar 15 1997