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 A246222 #8 Jan 12 2015 09:39:23 %S A246222 99,0,13303,530432,2715243,14872704,712988175,2114735616,14553496947, %T A246222 22338508875,9307563626682,839345640802598,8486108520773778, %U A246222 298020352385025000,10432593658200450596,210875469472380711300,944599826416703171100,12667164470975664000000 %N A246222 Number of permutations of [n] with exactly two (possibly overlapping) occurrences of the consecutive step pattern given by the binary expansion of n, where 1=up and 0=down. %H A246222 Alois P. Heinz, <a href="/A246222/b246222.txt">Table of n, a(n) for n = 7..130</a> %Y A246222 Column k=2 of A242783. %K A246222 nonn %O A246222 7,1 %A A246222 _Alois P. Heinz_, Aug 19 2014