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 A158428 #4 Feb 16 2025 08:33:09
%S A158428 1,26,461,7104,103479,1481275,21284288,311031666,4663993186,
%T A158428 72241115375,1161657944287
%N A158428 Number of permutations of 1..n containing the relative rank sequence { 42513 } at any spacing.
%C A158428 Same series for 24153 31524 35142
%H A158428 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PermutationPattern.html">Permutation Pattern</a>
%Y A158428 A056986 A158005
%K A158428 nonn
%O A158428 5,2
%A A158428 _R. H. Hardin_ Mar 18 2009