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A091220 Number of divisors of the n-th GF(2)[X]-polynomial. 13
1, 2, 2, 3, 3, 4, 2, 4, 4, 6, 2, 6, 2, 4, 4, 5, 5, 8, 2, 9, 3, 4, 4, 8, 2, 4, 6, 6, 4, 8, 2, 6, 4, 10, 4, 12, 2, 4, 6, 12, 2, 6, 4, 6, 8, 8, 2, 10, 4, 4, 6, 6, 4, 12, 2, 8, 6, 8, 2, 12, 2, 4, 6, 7, 9, 8, 2, 15, 3, 8, 4, 16, 2, 4, 8, 6, 4, 12, 4, 15, 3, 4, 8, 9, 7, 8, 2, 8, 4, 16, 2, 12, 4, 4, 6, 12, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
PROG
(PARI) a(n)=local(p, fm, k); while(n>0, p+=Mod(n, 2)*x^k; n\=2; k++); fm=factor(p); prod(k=1, matsize(fm)[1], fm[k, 2]+1) \\ Franklin T. Adams-Watters, Jun 22 2010
CROSSREFS
a(n) = A000005(A091203(n)) = A000005(A091205(n)). Cf. A091257.
Sequence in context: A116619 A337776 A366611 * A057955 A305788 A116473
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 03 2004
STATUS
approved

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Last modified March 28 10:31 EDT 2024. Contains 371240 sequences. (Running on oeis4.)