OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
EXAMPLE
A000040(20) = 71, gcd(20, (71-1)*(71+1)) = 10 * gcd(2, 7*72) = 20 = a(20).
MATHEMATICA
Table[ GCD[n, Prime[n]^2 - 1], {n, 1, 100} ]
PROG
(PARI) { for (n=1, 1000, write("b064830.txt", n, " ", gcd(n, prime(n)^2 - 1)) ) } \\ Harry J. Smith, Sep 27 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 23 2001
STATUS
approved