A093396 -id:A093396 - cp's OEIS frontend

A093394 a(n) is the GCD of n and the product of the anti-divisors of n.

1, 1, 1, 2, 1, 1, 3, 2, 1, 4, 1, 2, 15, 1, 1, 6, 1, 4, 21, 2, 1, 8, 5, 2, 27, 4, 1, 30, 1, 1, 33, 2, 35, 12, 1, 2, 39, 8, 1, 42, 1, 4, 45, 2, 1, 16, 7, 10, 51, 4, 1, 54, 55, 8, 57, 2, 1, 60, 1, 2, 63, 1, 65, 66, 1, 4, 69, 70, 1, 24, 1, 2, 75, 4

Offset: 3

Lior Manor, Mar 28 2004

nonn

See A066272 for definition of anti-divisor.

			The anti-divisors of 18 are 4, 5, 7, 12. Hence a(18) = gcd(4*5*7*12, 18) = 6.

Cf. A066417, A091507, A093395, A093396.

a(n) = gcd(n, A091507(n)).

A093395 Numerators of n divided by the product of the anti-divisors of n.

Original entry on oeis.org

3, 4, 5, 3, 7, 8, 3, 5, 11, 3, 13, 7, 1, 16, 17, 3, 19, 5, 1, 11, 23, 3, 5, 13, 1, 7, 29, 1, 31, 32, 1, 17, 1, 3, 37, 19, 1, 5, 41, 1, 43, 11, 1, 23, 47, 3, 7, 5, 1, 13, 53, 1, 1, 7, 1, 29, 59, 1, 61, 31, 1, 64, 1, 1, 67, 17, 1, 1, 71, 3, 73, 37, 1, 19

Offset: 3

Lior Manor, Mar 28 2004

See A066272 for definition of anti-divisor.

			The anti-divisors of 18 are 4, 5, 7, 12. Hence a(18) = 18/GCD(4*5*7*12, 18) = 3.

Cf. A066417, A091507, A093394, A093396 (denominators).

a(n) = n/GCD(n, A091507(n)) = n/A093394(n)

Name changed by Franklin T. Adams-Watters, Aug 21 2013

cp's OEIS Frontend

A093394 a(n) is the GCD of n and the product of the anti-divisors of n.

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