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 A249249 #7 Jan 12 2015 10:50:12
%S A249249 0,0,0,1,3,50,270,840,5376,166320,2903040,20956320,191600640,
%T A249249 4203239040,29059430400,119870150400,1598268672000,112634352230400,
%U A249249 4623936565248000,61498356317798400,1773991047628800000,69256610499428352000,1061556242901073920000
%N A249249 Total number of occurrences of the consecutive step pattern given by the binary expansion of n (where 1=up and 0=down) in all permutations of [n].
%H A249249 Alois P. Heinz, <a href="/A249249/b249249.txt">Table of n, a(n) for n = 0..130</a>
%F A249249 a(n) = Sum_{k>0} k*A242783(n,k).
%Y A249249 Cf. A242783.
%K A249249 nonn
%O A249249 0,5
%A A249249 _Alois P. Heinz_, Jan 12 2015