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 A291507 #23 Jul 16 2020 09:11:35 %S A291507 0,1,513,10097891,2647111616000,5170142516807540224, %T A291507 52103129720841632885243904,2102549272223560776918400601161728, %U A291507 282199388424234851655058321255905292713984,109329825340451764123791003609208862665771818418176 %N A291507 a(n) = (n!)^9 * Sum_{i=1..n} 1/i^9. %H A291507 Seiichi Manyama, <a href="/A291507/b291507.txt">Table of n, a(n) for n = 0..75</a> %F A291507 a(0) = 0, a(1) = 1, a(n+1) = (n^9+(n+1)^9)*a(n) - n^18*a(n-1) for n > 0. %F A291507 a(n) ~ zeta(9) * (2*Pi)^(9/2) * n^(9*n+9/2) / exp(9*n). - _Vaclav Kotesovec_, Aug 27 2017 %F A291507 Sum_{n>=0} a(n) * x^n / (n!)^9 = polylog(9,x) / (1 - x). - _Ilya Gutkovskiy_, Jul 15 2020 %t A291507 Table[(n!)^9 * Sum[1/i^9, {i, 1, n}], {n, 0, 12}] (* _Vaclav Kotesovec_, Aug 27 2017 *) %o A291507 (PARI) a(n) = n!^9*sum(i=1, n, 1/i^9); \\ _Michel Marcus_, Aug 26 2017 %Y A291507 Cf. A000254 (k=1), A001819 (k=2), A066989 (k=3), A099827 (k=5), A291456 (k=6), A291505 (k=7), A291506 (k=8), this sequence (k=9), A291508 (k=10). %Y A291507 Column k=9 of A291556. %K A291507 nonn %O A291507 0,3 %A A291507 _Seiichi Manyama_, Aug 25 2017