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A071889 GCD(A071888(n),n). 6
1, 2, 3, 2, 5, 2, 7, 2, 3, 2, 11, 2, 13, 7, 3, 2, 17, 3, 19, 2, 3, 2, 23, 2, 5, 2, 3, 2, 29, 3, 31, 2, 3, 2, 7, 2, 37, 2, 3, 2, 41, 2, 43, 2, 3, 2, 47, 3, 7, 5, 3, 2, 53, 3, 5, 2, 3, 2, 59, 2, 61, 2, 3, 2, 5, 3, 67, 2, 3, 2, 71, 2, 73, 2, 3, 2, 7, 2, 79, 2, 3, 2, 83, 2, 5, 2, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For n>1: a(n)=n iff n is prime.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

PROG

(Haskell)

a071889 n = gcd n $ a071888 n  -- Reinhard Zumkeller, Jun 10 2012

(PARI) a(n)=if(n<2, return(1)); my(m=n+1); while(gcd(m++, n)==1 || !issquarefree(m), ); gcd(n, m-n) \\ Charles R Greathouse IV, May 29 2014

CROSSREFS

Cf. A071892.

Sequence in context: A092067 A214606 A079879 * A091963 A067695 A285336

Adjacent sequences:  A071886 A071887 A071888 * A071890 A071891 A071892

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jun 10 2002

STATUS

approved

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Last modified December 13 00:17 EST 2017. Contains 295954 sequences.