1,3

For n >= 3, a(n) is the largest term of A014580 less than n.

Antti Karttunen, Table of n, a(n) for n = 1..21845

Index entries for sequences related to polynomials in ring GF(2)[X]

(PARI)

A091225(n) = polisirreducible(Pol(binary(n))*Mod(1, 2));

A305419(n) = if(n<3, 1, my(k=n-1); while(k>1 && !A091225(k), k--); (k));

Cf. A014580, A091225, A305420, A305422.

Cf. also A151799 (A136548), A305429.

Sequence in context: A200924 A111913 A210796 * A075757 A096420 A096193

Adjacent sequences: A305416 A305417 A305418 * A305420 A305421 A305422

nonn

Antti Karttunen, Jun 07 2018

approved