a(n) = prime(n)*(prime(n-1)-1)/2.

Terms

a(0) =5a(1) =14a(2) =33a(3) =65a(4) =102a(5) =152a(6) =207a(7) =319a(8) =434a(9) =555a(10) =738a(11) =860a(12) =987a(13) =1219a(14) =1534a(15) =1769a(16) =2010a(17) =2343a(18) =2555a(19) =2844a(20) =3237a(21) =3649a(22) =4268a(23) =4848a(24) =5150a(25) =5457a(26) =5777a(27) =6102a(28) =7112a(29) =8253