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 A177295 #5 Jan 25 2016 15:49:21 %S A177295 1,1,20,1680,369600,168168000,137225088000,67280653440000, %T A177295 22859094527068800,6325233865588881600 %N A177295 Number of permutations of 3 copies of 1..n with all adjacent differences <= 5 in absolute value. %C A177295 a(n) = (3n)!/6^n for n<=6. %Y A177295 Cf. A014606. %K A177295 nonn %O A177295 0,3 %A A177295 _R. H. Hardin_, May 06 2010