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 A074988 #11 Mar 30 2012 18:58:42
%S A074988 1,3,7,14,29,59,119,238,476,953,1907,3814,7629,15259,30519,61038,
%T A074988 122077,244154,488309,976618,1953237,3906475,7812951,15625902,
%U A074988 31251804,62503609,125007218,250014436,500028873,1000057747,2000115495
%N A074988 Numbers n such that the k-th binary digit of n equals mu(k)^2 for k=1 up to A029837(n+1).
%F A074988 a(n+1)=2*a(n)+mu(n+1)^2 a(n)=sum(i=1, n, mu(i)^2*2^(n-i))
%F A074988 a(n)=sum{k=0..n, abs(mu(n-k+1))*2^k}; - _Paul Barry_, Jul 20 2005
%e A074988 59 = 111011 and mu(1)^2,mu(2)^2,mu(3)^2,mu(4)^2,mu(5)^2,mu(6)^2 = 1,1,1,0,1,1 hence 59 is in the sequence
%o A074988 (PARI) a(n)=sum(i=1,n,moebius(i)^2*2^(n-i))
%Y A074988 Cf. A008683
%K A074988 base,easy,nonn
%O A074988 1,2
%A A074988 _Benoit Cloitre_, Oct 02 2002