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 A226285 #15 Jul 12 2024 15:15:58 %S A226285 0,0,0,0,0,0,0,576,14400,360000,6480000,116640000,1905120000, %T A226285 31116960000,497871360000,7965941760000,129048256512000, %U A226285 2090581755494400,34843029258240000,580717154304000000,10038110810112000000,173515915431936000000,3123286477774848000000 %N A226285 a(n) = [n/2]!*[(n+1)/2]!*C([n/2],4)*C([(n+1)/2],4). %C A226285 Number of permutations of n elements with 8 odd displacements. %C A226285 Column 5 of A226288. %C A226285 Column k=8 of A145893, a diagonal of A145894. - _Alois P. Heinz_, May 29 2014 %H A226285 R. H. Hardin, <a href="/A226285/b226285.txt">Table of n, a(n) for n = 1..210</a> %t A226285 a[n_]:= Floor[n/2]!*Floor[(n+1)/2]!*Binomial[Floor[n/2],4]*Binomial[Floor[(n+1)/2],4]; Array[a,21] (* _Stefano Spezia_, Jul 12 2024 *) %Y A226285 Cf. A145893, A145894, A226288. %K A226285 nonn %O A226285 1,8 %A A226285 _R. H. Hardin_, connection of formula with combinatoric problem via _N. J. A. Sloane_ in the Sequence Fans Mailing List, Jun 02 2013