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 A122466 #9 Oct 27 2024 20:29:14
%S A122466 100,110,1001,1010,1110,1111,10101,10110,11001,11010,100001,100010,
%T A122466 100011,100110,100111,101110,110001,110011,110111,111001,111010,
%U A122466 111110,1000001,1000101,1001010,1001101,1010010,1010101,1010110,1010111,1011011,1011101,1011110,1011111
%N A122466 Semiprimes written in base 2.
%C A122466 Semiprime analog of A004676 Primes written in base 2. Partial sums are A122467; equivalently, this sequence is the first differences of A122467.
%F A122466 a(n) = A007088(A001358(n)).
%t A122466 lim=100;SP=Select[Range[lim],PrimeOmega[#]==2&];ll=Length[SP];Table[FromDigits[IntegerDigits[SP[[n]],2]],{n,ll}] (* _James C. McMahon_, Oct 27 2024 *)
%Y A122466 Cf. A001358, A007088, A004676, A122467.
%K A122466 base,easy,nonn
%O A122466 1,1
%A A122466 _Jonathan Vos Post_, Sep 09 2006
%E A122466 a(31)-a(34) from _James C. McMahon_, Oct 27 2024