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A294881
Number of proper divisors of n that are irreducible when their binary expansion is interpreted as polynomial over GF(2).
5
0, 0, 0, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 2, 1, 1, 0, 2, 0, 1, 2, 2, 0, 2, 0, 2, 1, 2, 0, 2, 0, 1, 2, 1, 1, 2, 0, 2, 2, 1, 0, 3, 0, 2, 1, 1, 0, 2, 1, 2, 1, 2, 0, 2, 1, 2, 2, 1, 0, 2, 0, 2, 2, 1, 1, 3, 0, 1, 1, 2, 0, 2, 0, 2, 2, 2, 2, 3, 0, 1, 1, 2, 0, 3, 0, 1, 1, 2, 0, 2, 2, 1, 2, 2, 1, 2, 0, 2, 2, 2, 0, 2, 0, 2, 2
OFFSET
1,6
FORMULA
a(n) = Sum_{d|n, d < n} A091225(d).
a(n) + A294882(n) = A032741(n).
a(n) = A294883(n) - A091225(n).
PROG
(PARI) A294881(n) = sumdiv(n, d, (d<n) * polisirreducible(Mod(1, 2) * Pol(binary(d))));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 09 2017
STATUS
approved