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 A373857 #12 Jun 19 2024 09:28:13 %S A373857 0,1,3,32,734,28994,1752046,150262104,17356844088,2597710341600, %T A373857 488957612319984,113044488306692304,31490845086661001664, %U A373857 10403092187976909854640,4021236906890850070201488,1798052050351216209712206336,920859156623446912386646303104 %N A373857 a(n) = Sum_{k=1..n} k! * k^(n-1) * Stirling1(n,k). %F A373857 E.g.f.: Sum_{k>=1} log(1 + k*x)^k / k. %t A373857 nmax=16; Range[0,nmax]!CoefficientList[Series[Sum[(Log[1 + k*x])^k / k,{k,nmax}],{x,0,nmax}],x] (* _Stefano Spezia_, Jun 19 2024 *) %o A373857 (PARI) a(n) = sum(k=1, n, k!*k^(n-1)*stirling(n, k, 1)); %Y A373857 Cf. A092552, A244585, A373855. %Y A373857 Cf. A320082, A320083. %K A373857 nonn %O A373857 0,3 %A A373857 _Seiichi Manyama_, Jun 19 2024