A071889 a(n) = gcd(A071888(n), n).

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

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. A071888, A071892.

Sequence in context: A356838 A079879 A381319 * A381131 A091963 A067695

Adjacent sequences: A071886 A071887 A071888 * A071890 A071891 A071892

Keyword

nonn

Author

Reinhard Zumkeller, Jun 10 2002

Status

approved