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 A158426 #4 Feb 16 2025 08:33:09
%S A158426 1,26,460,7071,102788,1469419,21101676,308396208,4627521637,
%T A158426 71750494216,1155187096545
%N A158426 Number of permutations of 1..n containing the relative rank sequence { 41523 } at any spacing.
%C A158426 Same series for 32514 34152 25143 24513 42153 31542 35124
%H A158426 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PermutationPattern.html">Permutation Pattern</a>
%Y A158426 A056986 A158005
%K A158426 nonn
%O A158426 5,2
%A A158426 _R. H. Hardin_ Mar 18 2009