A084310 a(n) = gcd(prime(n)+1, n).

1, 2, 3, 4, 1, 2, 1, 4, 3, 10, 1, 2, 1, 2, 3, 2, 1, 2, 1, 4, 1, 2, 1, 6, 1, 2, 1, 4, 1, 6, 1, 4, 3, 2, 5, 4, 1, 2, 3, 2, 1, 14, 1, 2, 9, 2, 1, 16, 1, 10, 3, 4, 1, 18, 1, 8, 3, 2, 1, 6, 1, 2, 7, 8, 1, 6, 1, 2, 3, 70, 1, 72, 1, 2, 5, 4, 1, 2, 1, 10, 3, 2, 1, 14, 5, 2, 3, 2, 1, 2, 13, 4, 1, 2, 5, 24, 1, 2, 1, 2

Offset

1,2

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Maple

A084310:= n-> igcd(ithprime(n)+1, n): seq(A084310(n), n=1..150); # Wesley Ivan Hurt, Jan 27 2017

Mathematica

Table[GCD[Prime[w]+1, w], {w, 128}]

Prog

(PARI) a(n) = gcd(prime(n)+1, n); \\ Michel Marcus, Jan 27 2017

Crossrefs

Cf. A084309, A084311, A084312, A084313, A084314, A084315, A084316.

Sequence in context: A298160 A118310 A073057 * A214063 A078978 A322424

Adjacent sequences: A084307 A084308 A084309 * A084311 A084312 A084313

Keyword

nonn,easy

Author

Labos Elemer, Jun 13 2003

Status

approved