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 A198809 #17 Feb 06 2024 08:12:42
%S A198809 1,39916800,548828480360160000,23934366266775567482880000000,
%T A198809 1746930746117010628955362040959500000000,
%U A198809 170878335353097656943918169452451079403744627916800,20193738534370392855946567010492898163504440783192016158720000
%N A198809 Number of closed paths of length 11n whose steps are 11th roots of unity.
%C A198809 Equivalently, the number of paths of length 11n in Z^11 from {0}^11 to {n}^11. - _Andrew Howroyd_, Nov 01 2018
%H A198809 Andrew Howroyd, <a href="/A198809/b198809.txt">Table of n, a(n) for n = 0..50</a>
%H A198809 Gilbert Labelle and Annie Lacasse, <a href="https://doi.org/10.46298/dmtcs.2937">Closed paths whose steps are roots of unity</a>, in FPSAC 2011, Reykjavik, Iceland DMTCS proc. AO, 2011, 599-610.
%F A198809 a(n) = (11*n)!/(n!)^11. - _Andrew Howroyd_, Nov 01 2018
%o A198809 (PARI) a(n) = (11*n)!/(n!)^11; \\ _Andrew Howroyd_, Nov 01 2018
%Y A198809 Row n=11 of A187783, column k=11 of A089759.
%K A198809 nonn
%O A198809 0,2
%A A198809 _Simon Plouffe_, Oct 30 2011
%E A198809 Sequence redefined and a(2)-a(6) from _Andrew Howroyd_, Nov 01 2018