A122466 - OEIS

%I #5 Jul 11 2015 11:28:21

%S 100,110,1001,1010,1110,1111,10101,10110,11001,11010,100001,100010,

%T 100011,100110,100111,101110,110001,110011,110111,111001,111010,

%U 111110,1000001,1000101,1001010,1001101,1010010,1010101,1010110,1010111

%N Semiprimes written in base 2.

%C Semiprime analog of A004676 Primes written in base 2. Partial sums are A122467; equivalently, this sequence is the first differences of A122467.

%F a(n) = A007088(A001358(n)).

%Y Cf. A001358, A007088, A004676, A122467.

%K base,easy,nonn

%O 1,1

%A _Jonathan Vos Post_, Sep 09 2006