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 A246223 #8 Jan 12 2015 09:41:30 %S A246223 12,0,0,158720,74601,0,59062275,17730048,2099186631,10006375, %T A246223 206421198786,135518026916798,569885619485772,13007265031125000, %U A246223 5556193492800826418,52483739349674666340,51836903694327604380,388109358965377200000,302747316148839193725590 %N A246223 Number of permutations of [n] with exactly three (possibly overlapping) occurrences of the consecutive step pattern given by the binary expansion of n, where 1=up and 0=down. %H A246223 Alois P. Heinz, <a href="/A246223/b246223.txt">Table of n, a(n) for n = 7..130</a> %Y A246223 Column k=3 of A242783. %K A246223 nonn %O A246223 7,1 %A A246223 _Alois P. Heinz_, Aug 19 2014