OFFSET
1,8
COMMENTS
4 divides a(n) for n > 0.
FORMULA
a(n) = 2*Sum_{i=1..n} i * (pi(i-3) - pi(i-4)) * (pi(i+3) - pi(i+2)), where pi is the prime counting function (A000720).
a(n) = Sum_{i=1..2*n} c(i), where c is the characteristic function of A104010. - R. J. Mathar, May 28 2013
MAPLE
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, May 24 2013
STATUS
approved