A122466 Semiprimes written in base 2.

100, 110, 1001, 1010, 1110, 1111, 10101, 10110, 11001, 11010, 100001, 100010, 100011, 100110, 100111, 101110, 110001, 110011, 110111, 111001, 111010, 111110, 1000001, 1000101, 1001010, 1001101, 1010010, 1010101, 1010110, 1010111

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..30.

Formula

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

Crossrefs

Cf. A001358, A007088, A004676, A122467.

Sequence in context: A162530 A204590 A115454 * A066511 A281193 A285776

Adjacent sequences: A122463 A122464 A122465 * A122467 A122468 A122469

Keyword

base,easy,nonn

Author

Jonathan Vos Post, Sep 09 2006

Status

approved