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A191906 The remainder of (product of proper divisors of n) mod (sum of proper divisors of n). 6
0, 0, 2, 0, 0, 0, 1, 3, 2, 0, 0, 0, 4, 6, 4, 0, 9, 0, 4, 10, 8, 0, 0, 5, 10, 1, 0, 0, 36, 0, 1, 3, 14, 9, 41, 0, 16, 5, 0, 0, 0, 0, 16, 12, 20, 0, 44, 7, 6, 9, 36, 0, 54, 4, 0, 11, 26, 0, 0, 0, 28, 33, 8, 8, 66, 0, 42, 15, 10, 0, 81, 0, 34, 39, 16, 1, 72, 0, 10, 9, 38, 0, 84, 16, 40, 21 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

LINKS

Antti Karttunen, Table of n, a(n) for n = 2..16384

Antti Karttunen, Data supplement: n, a(n) computed for n = 2..65537

FORMULA

a(n) = A007956(n) mod A001065(n).

EXAMPLE

a(2) = 1 mod 1 = 0;

a(3) = 1 mod 1 = 0;

a(4) = 2 mod 3 = 2.

MAPLE

A007956 := n -> mul(i, i=op(numtheory[divisors](n) minus {1, n}));

A001065 := proc(n) numtheory[sigma](n)-n ; end proc:

A191906 := proc(n) A007956(n) mod A001065(n) ; end proc:

seq(A191906(n), n=2..90) ; # R. J. Mathar, Jun 25 2011

PROG

(PARI) A191906(n) = { my(m=1, s=0); fordiv(n, d, if(d<n, m *= d; s += d)); (m%s); }; \\ Antti Karttunen, Jul 11 2019

CROSSREFS

Cf. A001065, A007956, A187680.

Sequence in context: A244233 A227345 A123262 * A187080 A301342 A226369

Adjacent sequences:  A191903 A191904 A191905 * A191907 A191908 A191909

KEYWORD

nonn,look

AUTHOR

Juri-Stepan Gerasimov, Jun 19 2011

STATUS

approved

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Last modified September 18 02:09 EDT 2020. Contains 337164 sequences. (Running on oeis4.)