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A062754
a(n) = gcd(n, sigma(n+1)).
2
1, 2, 1, 2, 1, 2, 1, 1, 9, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 4, 3, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 16, 3, 2, 7, 2, 1, 2, 3, 2, 1, 2, 1, 2, 9, 2, 1, 3, 1, 2, 1, 2, 1, 18, 5, 8, 3, 2, 1, 2, 1, 2, 1, 4, 1, 2, 1, 4, 3, 2, 1, 2, 1, 2, 5, 4, 7, 2, 1, 1, 9, 2, 1, 12, 1, 2, 3, 2, 1, 2, 7, 4, 3, 2, 1, 2, 1, 2, 1, 2, 1, 2
OFFSET
1,2
LINKS
MATHEMATICA
Table[GCD[n, DivisorSigma[1, n+1]], {n, 110}] (* Harvey P. Dale, May 25 2015 *)
PROG
(PARI) j=[]; for(n=1, 200, j=concat(j, gcd(n, sigma(n+1)))); j
(PARI) a(n) = gcd(n, sigma(n+1)); \\ Michel Marcus, Dec 16 2017
CROSSREFS
Sequence in context: A069349 A167404 A280223 * A342846 A045888 A335885
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 15 2001
STATUS
approved