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 A090002 #10 Jul 28 2022 11:59:12
%S A090002 0,1,2,2,1,4,1,3,1,2,3,1,3,2,2,4,1,2,2,5,2,3,6,1,2,1,5,4,2,2,3,5,1,2,
%T A090002 2,3,2,6,3,2,2,3,3,3,4,2,3,2,2,2,5,3,2,3,3,2,4,3,4,3,3,3,4,6,1,2,2,3,
%U A090002 1,4,2,7,1,2,3,2,3,3,2,2,2,5,2,4,5,3,3,4,4,5,12,2,2,2,3,3,2,1,4,2,3,5
%N A090002 Length of longest contiguous block of 1's in binary expansion of n-th triangular number.
%C A090002 a(n) = A038374(A000217(n)).
%H A090002 Antti Karttunen, <a href="/A090002/b090002.txt">Table of n, a(n) for n = 0..16384</a>
%H A090002 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%t A090002 Join[{0},Max[Length/@Select[Split[IntegerDigits[#,2]],#[[1]]==1&]]&/@ Accumulate[ Range[110]]] (* _Harvey P. Dale_, Jul 28 2022 *)
%Y A090002 Cf. A000120, A090001, A090003, A089999, A090048.
%K A090002 nonn,base
%O A090002 0,3
%A A090002 _Reinhard Zumkeller_, Nov 20 2003