A079080 a(n) = gcd((prime(n)+1)*(prime(n+1)+1)/4, prime(n)*prime(n+1)+1).

1, 2, 12, 6, 6, 3, 18, 6, 4, 60, 4, 3, 42, 6, 4, 2, 30, 2, 6, 36, 8, 6, 2, 3, 3, 204, 6, 54, 3, 48, 6, 2, 138, 6, 300, 4, 2, 6, 4, 2, 90, 12, 96, 3, 396, 10, 14, 6, 114, 3, 8, 120, 6, 2, 4, 4, 540, 4, 3, 282, 6, 6, 6, 156, 3, 6, 2, 6, 174, 3, 4, 6, 4, 2, 6, 4, 3, 3, 15, 6, 210, 12, 216, 4, 6, 2

Offset

1,2

Comments

a(n) = gcd(A079079(n), A023523(n+1)).

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Prog

(Haskell)
a079080 n = a079079 n `gcd` a023523 (n + 1)
-- Reinhard Zumkeller, Oct 09 2012

Crossrefs

Cf. A079081, A079082.

Sequence in context: A286256 A239111 A112100 * A228454 A278255 A345469

Adjacent sequences: A079077 A079078 A079079 * A079081 A079082 A079083

Keyword

nonn

Author

Reinhard Zumkeller, Dec 22 2002

Status

approved