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A345375 Number of unitary prime divisors of n whose prime index is even. 0
0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 2, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 2, 0, 0, 2, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 2, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 2, 1, 0, 0, 0, 0, 2, 0, 1, 2, 0, 1, 0, 2, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,21

LINKS

Table of n, a(n) for n=1..93.

FORMULA

a(n) = Sum_{p|n, p prime} ((pi(p)+1) mod 2) * floor(1/gcd(p,n/p)).

CROSSREFS

Cf. A056169.

Sequence in context: A025462 A024879 A024316 * A101669 A243067 A086965

Adjacent sequences:  A345372 A345373 A345374 * A345376 A345377 A345378

KEYWORD

nonn

AUTHOR

Wesley Ivan Hurt, Jun 16 2021

STATUS

approved

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Last modified September 27 11:53 EDT 2021. Contains 347689 sequences. (Running on oeis4.)