A180172 a(n) = gcd(prime(n)+2, n).

1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 11, 3, 1, 1, 1, 1, 1, 9, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 5, 1, 1, 1, 1, 1, 9, 1, 1, 13, 5, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 5, 11, 1, 1, 1, 1, 71, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 15, 7, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1

Offset

1,6

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Mathematica

Table[GCD[n, Prime[n]+2], {n, 200}]

Prog

(Magma) [GCD(n, NthPrime(n) +2): n in [1..110]]; // G. C. Greubel, Mar 12 2023
(SageMath) [gcd(nth_prime(n) + 2, n) for n in range(1, 111)] # G. C. Greubel, Mar 12 2023

Crossrefs

Cf. A003989, A052147, A084309, A084310, A180173.

Sequence in context: A141901 A200473 A361948 * A327372 A328323 A090751

Adjacent sequences: A180169 A180170 A180171 * A180173 A180174 A180175

Keyword

nonn

Author

Zak Seidov, Aug 15 2010

Status

approved