A294883 Number of divisors of n that are irreducible when their binary expansion is interpreted as polynomial over GF(2).

0, 1, 1, 1, 0, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 0, 2, 1, 1, 2, 2, 0, 2, 1, 2, 1, 2, 0, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 3, 0, 2, 1, 1, 1, 2, 1, 2, 1, 2, 0, 2, 2, 2, 2, 1, 1, 2, 1, 2, 2, 1, 1, 3, 1, 1, 1, 2, 0, 2, 1, 2, 2, 2, 2, 3, 0, 1, 1, 2, 0, 3, 0, 1, 2, 2, 0, 2, 3, 1, 2, 2, 1, 2, 1, 2, 2, 2, 0, 2, 1, 2, 2

Offset: 1

Author

Antti Karttunen, Nov 09 2017

Keywords

• nonn

Comments

Number of terms of A014580 that divide n.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..21845
• Index entries for sequences related to polynomials in ring GF(2)[X]

Crossrefs

Cf. A000005, A014580, A091225, A294881, A294884.

Cf. A091209 (gives a subset of zeros).

Cf. also A234741, A234742, A294893.

Programs

PARI

A294883(n) = sumdiv(n,d,polisirreducible(Mod(1, 2)*Pol(binary(d))));

Formula

a(n) = Sum_{d|n} A091225(d).

a(n) + A294884(n) = A000005(n).

a(n) = A294881(n) + A091225(n).