OFFSET
1,4
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..12250
EXAMPLE
2*(2+1)-1=5, 2*(2+1)+1=7 5 and 7 twin primes, p(1)=2 so a(1)=1
3*(3+1)-1=11, 3*(3+1)=13 11 and 13 twin primes,p(2)=3 so a(2)=1
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Aug 05 2008
STATUS
approved