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 A091347 #9 Jun 17 2023 07:35:28
%S A091347 0,1,15,115,675,3451,16275,72955,316275,1340251,5590035,23054395,
%T A091347 94314675,383578651,1553331795,6270493435,25253701875,101530450651,
%U A091347 407669649555,1635323974075,6555235693875,26262769508251,105176572911315,421082805640315,1685460823266675,6745232212623451
%N A091347 a(n) = 6*4^n - 12*3^n + 7*2^n - 1.
%H A091347 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (10, -35, 50, -24).
%F A091347 a(n) = Sum_{i=1..n} i!*i^3*Stirling2(n, i)*(-1)^(n-i).
%t A091347 Table[6*4^n - 12*3^n + 7*2^n - 1, {n, 0, 25}]
%o A091347 (PARI) a(n) = sum(i=1, n, i!*i^3*stirling(n, i, 2)*(-1)^(n-i)); \\ _Michel Marcus_, Oct 21 2022
%Y A091347 Cf. A091344, A091348.
%K A091347 easy,nonn
%O A091347 0,3
%A A091347 Mario Catalani (mario.catalani(AT)unito.it), Jan 03 2004
%E A091347 More terms from _Michel Marcus_, Oct 21 2022