A091247 - OEIS

A091247

Characteristic function of A091242: 1 if the n-th GF(2)[X] polynomial is reducible, 0 otherwise.

0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1

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OFFSET

0,1

LINKS

Table of n, a(n) for n=0..101.

A. Karttunen, Scheme-program for computing this sequence.

Index entries for characteristic functions

Index entries for sequences operating on GF(2)[X]-polynomials

FORMULA

a(n) = A066247(A091203(n)) = A066247(A091205(n)).

PROG

(PARI) a(n) = if (n<2, 0, ! polisirreducible(Mod(1, 2)*Pol(binary(n)))); \\ Michel Marcus, Apr 12 2015