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A066752
a(n) = gcd(prime(n)+1, n+1).
3
1, 1, 2, 1, 6, 7, 2, 1, 2, 1, 4, 1, 14, 1, 16, 1, 6, 1, 4, 3, 2, 1, 12, 5, 2, 3, 4, 1, 10, 1, 32, 33, 2, 35, 6, 1, 2, 1, 8, 1, 6, 1, 4, 1, 2, 1, 4, 7, 2, 1, 26, 1, 2, 1, 2, 3, 2, 1, 2, 1, 2, 21, 4, 13, 2, 1, 4, 1, 2, 1, 6, 1, 2, 1, 76, 1, 78, 1, 2, 1, 2, 1, 12, 1, 2, 3, 2, 1, 6, 1, 4, 3, 2, 1, 4, 1, 2, 9, 4
OFFSET
1,3
LINKS
EXAMPLE
a(23) = gcd(prime(23)+1,23+1) = gcd(83+1,24) = gcd(84,24) = 12*gcd(7,2) = 12.
MATHEMATICA
Table[GCD[Prime[w]+1, w+1], {w, 1, 128}]
PROG
(PARI) { for (n=1, 1000, write("b066752.txt", n, " ", gcd(prime(n) + 1, n + 1)) ) } \\ Harry J. Smith, Mar 22 2010
CROSSREFS
Cf. A000040.
Sequence in context: A172430 A325139 A084312 * A192329 A059364 A258870
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jan 16 2002
EXTENSIONS
More terms from Labos Elemer, Jun 13 2003
STATUS
approved