A091221 Number of distinct irreducible polynomials dividing n-th GF(2)[X]-polynomial.

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

Offset

1,6

Links

Robert Israel, Table of n, a(n) for n = 1..10000

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

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

Maple

f:= proc(n) local L, P, R, i;
  L:= convert(n, base, 2);
  P:= add(L[i]*X^(i-1), i=1..nops(L));
  R:= Factors(P) mod 2;
  nops(R[2]);
end proc:
map(f, [$1.200]); # Robert Israel, Oct 11 2024

Crossrefs

a(n) = A001221(A091203(n)) = A001221(A091205(n)). A000374(n) = a(A000051(n)).

Sequence in context: A379552 A265210 A023396 * A106495 A100428 A325169

Adjacent sequences: A091218 A091219 A091220 * A091222 A091223 A091224

Keyword

nonn

Author

Antti Karttunen, Jan 03 2004

Status

approved