%I
%S 2,7,18,35,58,89,130,177,236,303,376,459,556,659,768,895,1032,1181,
%T 1338,1505,1684,1875,2072,2283,2510,2743,2984,3241,3510,3787,4070,
%U 4377,4690,5021,5368,5721,6088,6467,6856,7257,7676,8107,8546,8995,9456,9923
%N Sum of oddindexed primes.
%C Partial sums of A031368.  _Michel Marcus_, Oct 27 2015
%e p_1=2, p_2=3 and p_3=5, therefore a(2) = p_1 + p_3 = 2 + 5 = 7.
%o (PARI) a(n)=if(n<1,0,sum(k=1,n, prime(2*k1)))
%Y Cf. A031368, A077126.
%K nonn
%O 1,1
%A _Jon Perry_, Nov 29 2002
