OFFSET
1,2
FORMULA
seq = if n even then n/2 else n. seq = if n is prime then n+1. Sumseq = Sumseq + seq for n=1, 2, ...
PROG
(PARI) a(n)={sum(k=1, n, if(isprime(k), k+1, if(k%2, k, k/2)))};
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, May 26 2003
EXTENSIONS
Edited by Charles R Greathouse IV, Oct 09 2009
STATUS
approved