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 A236231 #6 Jan 20 2014 18:59:49 %S A236231 0,0,0,1,0,1,1,13,1,18,68,142,237,862,1672,3188,1768,6078,16090,32566, %T A236231 62214,181695,380903,802572,1634880,3784693,7871112,17020646,36800640, %U A236231 78582498,168074511,206295476,209557176,490017420,1097340244,2222684855,5116364054 %N A236231 Number of binary words of length n with exactly 2 (possibly overlapping) occurrences of the subword given by the binary expansion of n. %H A236231 Alois P. Heinz, <a href="/A236231/b236231.txt">Table of n, a(n) for n = 0..1000</a> %Y A236231 Column k=2 of A233940. %K A236231 nonn %O A236231 0,8 %A A236231 _Alois P. Heinz_, Jan 20 2014