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 A165404 #3 Mar 31 2012 13:21:19 %S A165404 0,1,4,6,7,16,18,19,24,25,28,30,31,64,66,67,72,73,76,78,79,96,97,100, %T A165404 102,103,112,114,115,120,121,124,126,127,256,258,259,264,265,268,270, %U A165404 271,288,289,292,294,295,304,306,307,312,313,316,318,319,384,385,388 %N A165404 The positions of zeros in the top row of A163898 (and A163899). %C A165404 Equivalently, the positions of ones in the top row of A163904. %H A165404 A. Karttunen, <a href="/A165404/b165404.txt">Table of n, a(n) for n = 0..609</a> %Y A165404 a(n) = A025581(A165403(n)). Same sequence in binary: A165406. For n>0, A147600(n-1) seems to give the number of terms with binary width n. See also A163901. %K A165404 nonn %O A165404 0,3 %A A165404 _Antti Karttunen_, Sep 19 2009