OFFSET
1,2
COMMENTS
As difference of two odd primes, all terms of A230481(n) = prime(prime(2*n))-prime(2*prime(n)) are even, which motivates to define the present sequence.
Further values: a(100)=617, a(10^3)=9344, a(10^4)=114171, a(10^5)=1325772, a(10^6)=14979156; a(10^10)~2.2*10^11, a(10^20)~3.9*10^21, a(10^30)~5.5*10^31.
LINKS
M. F. Hasler, Table of n, a(n) for n = 1..10000
PROG
(PARI) a=n->(prime(prime(2*n))-prime(2*prime(n)))/2
CROSSREFS
KEYWORD
sign
AUTHOR
M. F. Hasler, Oct 20 2013
STATUS
approved