A255572 a(n) = Number of terms larger than one in range 0 .. n of A205783.

0, 0, 0, 0, 1, 1, 2, 2, 3, 4, 5, 5, 6, 6, 7, 8, 9, 9, 10, 10, 11, 12, 13, 13, 14, 14, 15, 16, 17, 17, 18, 18, 19, 20, 21, 22, 23, 23, 24, 25, 26, 26, 27, 27, 28, 29, 30, 30, 31, 32, 33, 34, 35, 35, 36, 36, 37, 38, 39, 39, 40, 40, 41, 42, 43, 44, 45, 45, 46, 46, 47, 47, 48, 48, 49, 50, 51, 51, 52, 52, 53, 53

Offset: 0

Author

Antti Karttunen, May 14 2015

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..8192

Crossrefs

Essentially one less than A255573 (after the initial zero).

Cf. A065855, A091245, A205783, A255574.

Programs

PARI

A255572_write_bfile(up_to_n) = { my(n,a_n=0); for(n=0, up_to_n, if(((n > 1) && !polisirreducible(Pol(binary(n)))),a_n++); write("b255572.txt", n, " ", a_n)); };
A255572_write_bfile(8192);

Formula

Other identities and observations. For all n >= 1:

a(n) = A255573(n) - 1.

a(n) <= A065855(n).

a(n) <= A091245(n).