login
A084311
a(n) = gcd(prime(n)-1,n-1).
4
1, 1, 2, 3, 2, 1, 2, 1, 2, 1, 10, 1, 4, 1, 2, 1, 2, 1, 6, 1, 4, 3, 2, 1, 24, 25, 2, 1, 4, 1, 6, 1, 8, 3, 2, 5, 12, 1, 2, 1, 2, 1, 2, 1, 4, 9, 2, 1, 2, 1, 2, 17, 4, 1, 2, 1, 4, 3, 2, 1, 6, 1, 2, 1, 8, 1, 66, 1, 2, 3, 2, 1, 6, 1, 2, 1, 4, 11, 2, 1, 2, 3, 2, 1, 6, 17, 2, 3, 4, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 9, 2, 1
OFFSET
1,3
LINKS
MATHEMATICA
Table[GCD[Prime[w]-1, w-1], {w, 1, 128}]
PROG
(PARI) a(n) = gcd(prime(n)-1, n-1); \\ Michel Marcus, May 04 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jun 13 2003
STATUS
approved