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 A090001 #7 Nov 28 2014 14:05:59
%S A090001 0,1,1,1,1,2,1,2,1,1,2,4,1,1,2,3,1,1,1,2,2,3,4,1,1,3,1,2,2,2,3,4,1,1,
%T A090001 1,2,1,2,2,5,2,2,3,3,4,6,1,1,1,2,3,1,1,5,2,4,2,2,2,2,3,3,4,5,1,1,1,2,
%U A090001 1,2,2,3,1,2,2,6,2,3,5,2,2,2,2,3,3,3,3,3,4,4,6,2,1,3,1,2,1,2,2,2,3,5
%N A090001 Length of longest contiguous block of 1's in binary expansion of n^2.
%C A090001 a(n) = A038374(A000290(n)).
%H A090001 Harvey P. Dale, <a href="/A090001/b090001.txt">Table of n, a(n) for n = 0..1000</a>
%t A090001 Join[{0},Table[Max[Length/@Select[Split[IntegerDigits[n^2,2]], MemberQ[ #,1]&]],{n,110}]] (* _Harvey P. Dale_, Nov 28 2014 *)
%Y A090001 Cf. A000120, A090003, A090002, A090000, A089998, A090047.
%K A090001 nonn,base
%O A090001 0,6
%A A090001 _Reinhard Zumkeller_, Nov 20 2003