OFFSET
1,2
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..1000
EXAMPLE
For n=6: gcd(n!!+1,n-1) = 1 and gcd(n!!+2,n-2)=2, so that a(6)=2.
MATHEMATICA
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jul 21 2012
STATUS
approved