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 A367475 #11 Dec 04 2023 06:57:55 %S A367475 1,6,54,636,9204,157584,3111312,69533472,1734229344,47733263232, %T A367475 1436801816448,46942939272960,1654215709835520,62533593070755840, %U A367475 2524077593084160000,108339176213529384960,4927173048408858531840,236673892535088351744000 %N A367475 Expansion of e.g.f. 1 / (1 + 2 * log(1 - x))^3. %F A367475 a(n) = (1/2) * Sum_{k=0..n} 2^k * (k+2)! * |Stirling1(n,k)|. %F A367475 a(0) = 1; a(n) = 2*Sum_{k=1..n} (2*k/n + 1) * (k-1)! * binomial(n,k) * a(n-k). %p A367475 A367475 := proc(n) %p A367475 option remember ; %p A367475 if n =0 then %p A367475 1; %p A367475 else %p A367475 2*add((2*k/n + 1) * (k-1)! * binomial(n,k) * procname(n-k),k=1..n) ; %p A367475 end if; %p A367475 end proc: %p A367475 seq(A367475(n),n=0..70) ; # _R. J. Mathar_, Dec 04 2023 %o A367475 (PARI) a(n) = sum(k=0, n, 2^k*(k+2)!*abs(stirling(n, k, 1)))/2; %Y A367475 Cf. A088500, A367474. %Y A367475 Cf. A354122, A367471. %K A367475 nonn %O A367475 0,2 %A A367475 _Seiichi Manyama_, Nov 19 2023