OFFSET
1,2
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..1000
EXAMPLE
prime(8)=19; gcd(19+1,8-1)=1 and gcd(19+2,8-2)=3, so a(8)=2.
MATHEMATICA
b[n_]:=Prime[n]; c[n_]:=n; Table[m=1; While[GCD[b[n]+m, c[n]-m]==1, m++]; m, {n, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jul 20 2012
STATUS
approved