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A060778 a(n) = gcd(A000005(n+1), A000005(n)). 4
1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 2, 2, 2, 4, 1, 1, 2, 2, 2, 2, 4, 2, 2, 1, 1, 4, 2, 2, 2, 2, 2, 2, 4, 4, 1, 1, 2, 4, 4, 2, 2, 2, 2, 6, 2, 2, 2, 1, 3, 2, 2, 2, 2, 4, 4, 4, 4, 2, 2, 2, 2, 2, 1, 1, 4, 2, 2, 2, 4, 2, 2, 2, 2, 2, 6, 2, 4, 2, 2, 5, 1, 2, 2, 4, 4, 4, 4, 2, 2, 4, 2, 2, 4, 4, 4, 2, 2, 6, 3, 1, 2, 2, 2, 8, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harry J. Smith, Table of n, a(n) for n=1..1000

MATHEMATICA

GCD@@@Partition[DivisorSigma[0, Range[110]], 2, 1] (* Harvey P. Dale, May 27 2014 *)

PROG

(PARI) { t=1; for (n=1, 1000, d=numdiv(n+1); write("b060778.txt", n, " ", gcd(d, t)); t=d; ) } \\ Harry J. Smith, Jul 11 2009

(PARI) a(n) = gcd(numdiv(n), numdiv(n+1)); \\ Michel Marcus, Jan 12 2018

CROSSREFS

Cf. A000005, A057921, A058074.

Sequence in context: A213911 A081355 A223708 * A096492 A053874 A170906

Adjacent sequences:  A060775 A060776 A060777 * A060779 A060780 A060781

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 26 2001

STATUS

approved

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Last modified June 20 00:47 EDT 2019. Contains 324223 sequences. (Running on oeis4.)