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 A177313 #15 May 16 2020 01:34:20 %S A177313 1,1,48620,60110030,161686253810,304100156874800,574996024253854586, %T A177313 1016915629343040544250,1745708356607370063330620, %U A177313 2911820015993491302722966990,4754502826758413615581742528138,7626389809822483147908697112197520,12055478550658617275428327115583119762 %N A177313 Number of permutations of 9 copies of 1..n with all adjacent differences <= 1 in absolute value. %C A177313 a(n) = (9n)!/362880^n = A172613(n) for n<=2. %H A177313 Andrew Howroyd, <a href="/A177313/b177313.txt">Table of n, a(n) for n = 0..200</a> %Y A177313 Column k=9 of A331562. %Y A177313 Cf. A172613. %K A177313 nonn %O A177313 0,3 %A A177313 _R. H. Hardin_, May 06 2010 %E A177313 a(0)=1 prepended by _Alois P. Heinz_, Jan 20 2020 %E A177313 Terms a(7) and beyond from _Andrew Howroyd_, May 15 2020