%I
%S 3,10,23,42,71,108,151,204,265,336,415,504,605,712,825,956,1095,1246,
%T 1409,1582,1763,1956,2155,2378,2607,2846,3097,3360,3631,3912,4205,
%U 4516,4833,5170,5519,5878,6251,6634,7031,7440,7861,8294,8737,9194,9657
%N Sum of even indexed primes.
%e a(2)=10 as p_1=2, p_2=3, p_3=5 and p_4=7, therefore a(2)=p_2+p_4=10
%o (PARI) pc=1; ps=0; forprime (p=2,500,pc=3pc; if (pc==1,ps=ps+p; print1(ps",")))
%K nonn
%O 1,1
%A _Jon Perry_, Nov 29 2002
