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 A158438 #6 Feb 16 2025 08:33:10
%S A158438 1,26,460,7068,102678,1466963,21058080,307716363,4617738409,
%T A158438 71616934495,1153427948275
%N A158438 Number of permutations of 1..n containing the relative rank sequence { 53124 } at any spacing.
%C A158438 Same series for 34251 32415 15243 51423 24531 42135 13542
%H A158438 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PermutationPattern.html">Permutation Pattern</a>
%Y A158438 Cf. A056986, A158005.
%K A158438 nonn
%O A158438 5,2
%A A158438 _R. H. Hardin_, Mar 18 2009