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 A348146 #17 Oct 03 2021 10:19:27 %S A348146 1,2,2,6,2,234,2,331842,46658,24883200258,2,139314179589392898,2, %T A348146 82606411253903523840004098,619173642242176782338, %U A348146 6984964247141514123665660725036072962,2,109110688415571335888754861121236891599318185050114,2 %N A348146 a(n) = Sum_{d|n} (d!)^(n-d). %H A348146 Seiichi Manyama, <a href="/A348146/b348146.txt">Table of n, a(n) for n = 1..61</a> %F A348146 a(p) = 2 for primes p. %F A348146 G.f.: Sum_{k>=1} x^k/(1 - (k! * x)^k). - _Seiichi Manyama_, Oct 03 2021 %t A348146 Table[Sum[(i!)^(n - i) (1 - Ceiling[n/i] + Floor[n/i]), {i, n}], {n, 20}] %o A348146 (PARI) a(n) = sumdiv(n, d, d!^(n-d)); \\ _Seiichi Manyama_, Oct 03 2021 %o A348146 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=1, N, x^k/(1-(k!*x)^k))) \\ _Seiichi Manyama_, Oct 03 2021 %Y A348146 Cf. A062363, A342628, A345465, A346196. %K A348146 nonn %O A348146 1,2 %A A348146 _Wesley Ivan Hurt_, Oct 02 2021