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A320005 Number of proper divisors of n of the form 6*k + 5. 7
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 2, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 2, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 2, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,55

LINKS

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

FORMULA

a(n) = A319995(n) - [+5 = n (mod 6)], where [ ] is the Iverson bracket, giving 1 only when n = -1 mod 6, and 0 otherwise.

a(n) = A320015(n) - A320001(n).

a(n) = A007814(A319992(n)).

PROG

(PARI) A320005(n) = if(!n, n, sumdiv(n, d, (d<n)*(5==(d%6))));

CROSSREFS

Cf. A293896, A319992, A319995, A320001, A320003, A320015.

Sequence in context: A165766 A102082 A030199 * A325414 A216510 A005089

Adjacent sequences:  A320002 A320003 A320004 * A320006 A320007 A320008

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 03 2018

STATUS

approved

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Last modified January 29 14:23 EST 2020. Contains 331338 sequences. (Running on oeis4.)