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 A177302 #10 Jan 19 2016 18:22:16 %S A177302 1,1,252,756756,457507512,184619047020,97087382008034, %T A177302 49254897805981056,22802419346927105088 %N A177302 Number of permutations of 5 copies of 1..n with all adjacent differences <= 2 in absolute value. %C A177302 a(n) = (5n)!/120^n for n<=3. %Y A177302 Cf. A014609. %K A177302 nonn,more %O A177302 0,3 %A A177302 _R. H. Hardin_, May 06 2010 %E A177302 a(0), a(8) from _Alois P. Heinz_, Jan 19 2016