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 A091754 #8 Sep 01 2025 03:06:15 %S A091754 1,80,9520,1786400,493292800,189065676800,96179539456000, %T A091754 62739188255744000,51070871935283200000,50753775178192486400000, %U A091754 60478693661116393062400000,85121458839683971088384000000,139713174879733993267265536000000,264509913735543445488643604480000000 %N A091754 Fifth column (m=6) of array A091752 ((-1,2)Stirling2). %F A091754 a(n) = A091752(n, 6), n>=3. %F A091754 a(n) = ((3*(n-2))!/((3^(n-2))*(n-2)!))*(9*n^2-27*n+12)/4! = A052502(n-2)*(9*n^2-27*n+12)/4!, n>=3. %F A091754 a(n) ~ (3/e)^(2*n-5/2) * n^(2*n-2) / 8. - _Amiram Eldar_, Sep 01 2025 %t A091754 a[n_] := ((3*(n-2))!/((3^(n-2))*(n-2)!))*(9*n^2-27*n+12)/4!; Array[a, 20, 3] (* _Amiram Eldar_, Sep 01 2025 *) %Y A091754 Cf. A052502, A091752. %K A091754 nonn,easy,changed %O A091754 3,2 %A A091754 _Wolfdieter Lang_, Feb 27 2004