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 A159109 #4 Feb 16 2025 08:33:10
%S A159109 1,37,891,18042,337134,6078371,108359977,1938212839,35109518705,
%T A159109 648102812344
%N A159109 Number of permutations of 1..n containing the relative rank sequence { 143265 } at any spacing.
%C A159109 Same series for 634521 143256 125436 652341 562341 215436 634512
%H A159109 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PermutationPattern.html">Permutation Pattern</a>
%Y A159109 A056986 A158005 A158423
%K A159109 nonn
%O A159109 6,2
%A A159109 _R. H. Hardin_ Apr 05 2009