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A066909 (product of primes < n that do not divide n) (mod n). 0
0, 1, 2, 3, 1, 5, 2, 1, 7, 1, 1, 1, 9, 3, 7, 7, 8, 17, 18, 9, 16, 15, 15, 1, 24, 1, 26, 13, 17, 1, 19, 9, 14, 23, 3, 23, 11, 31, 19, 1, 6, 37, 26, 21, 7, 45, 35, 35, 25, 41, 2, 17, 27, 1, 31, 43, 50, 41, 15, 49, 55, 9, 10, 51, 28, 37, 30, 13, 26, 47, 24, 13, 28, 27, 73, 73, 76, 43, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..79.

FORMULA

a(n) = A066838(n) modulo n. - Michel Marcus, May 20 2014

a(prime(n)) = A062347(n-1). - Michel Marcus, May 20 2014

EXAMPLE

a(8) = (3 * 5 * 7) (mod 8) = 1 because 3, 5 and 7 are the primes < 8 that do not divide 8.

PROG

(PARI) a(n) = prod(i=1, n-1, if (isprime(i) && (n%i) , i, 1)) % n; \\ Michel Marcus, May 20 2014

CROSSREFS

Cf. A062347, A066838.

Sequence in context: A322966 A173239 A214055 * A095195 A229961 A189074

Adjacent sequences:  A066906 A066907 A066908 * A066910 A066911 A066912

KEYWORD

nonn

AUTHOR

Leroy Quet, Jan 22 2002

STATUS

approved

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Last modified August 13 22:57 EDT 2020. Contains 336473 sequences. (Running on oeis4.)