OFFSET
1,8
COMMENTS
The number of partitions of 2n into exactly two parts such that the first part is an odd composite integer, n > 2.
LINKS
MAPLE
with(numtheory); seq(ceil(k/2)-(pi(2*k)-pi(k-1)), k=1..100);
MATHEMATICA
Table[Floor[(n + 1) / 2] - (PrimePi[2 n] - PrimePi[n - 1]), {n, 100}] (* Vincenzo Librandi, Dec 07 2016 *)
PROG
(PARI) a226983(n) = if(n==1, 0, ceil(n/2) - primepi(2*n) + primepi(n-1)) \\ Michael B. Porter, Jun 29 2013
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Wesley Ivan Hurt, Jun 25 2013
STATUS
approved