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A305807 Dirichlet inverse of A032742 (the largest proper divisor of n). 3
1, -1, -1, -1, -1, -1, -1, -1, -2, -3, -1, 1, -1, -5, -3, -1, -1, 0, -1, 1, -5, -9, -1, 3, -4, -11, -4, 1, -1, 5, -1, -1, -9, -15, -5, 6, -1, -17, -11, 5, -1, 7, -1, 1, -2, -21, -1, 5, -6, -8, -15, 1, -1, 4, -9, 7, -17, -27, -1, 19, -1, -29, -4, -1, -11, 11, -1, 1, -21, -3, -1, 8, -1, -35, -8, 1, -9, 13, -1, 9, -8, -39, -1, 29, -15, -41, -27, 11, -1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

FORMULA

a(1) = 1; for n > 1, a(n) = -Sum_{d|n, d<n} A032742(n/d)*a(d).

PROG

(PARI)

A032742(n) = if(1==n, n, n/vecmin(factor(n)[, 1]));

A305807(n) = if(1==n, 1, -sumdiv(n, d, if(d<n, A032742(n/d)*A305807(d), 0)));

CROSSREFS

Cf. A032742, A300236, A300239, A305808.

Sequence in context: A140737 A108756 A106178 * A205104 A215561 A108714

Adjacent sequences:  A305804 A305805 A305806 * A305808 A305809 A305810

KEYWORD

sign

AUTHOR

Antti Karttunen, Jun 13 2018

STATUS

approved

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Last modified May 24 06:53 EDT 2019. Contains 323529 sequences. (Running on oeis4.)