a(n) = Sum_{j=1..n} prime(j)*2^(j-2).

Terms

a(0) =1a(1) =4a(2) =14a(3) =42a(4) =130a(5) =338a(6) =882a(7) =2098a(8) =5042a(9) =12466a(10) =28338a(11) =66226a(12) =150194a(13) =326322a(14) =711346a(15) =1579698a(16) =3513010a(17) =7510706a(18) =16292530a(19) =34904754a(20) =73177778a(21) =156015282a(22) =330078898a(23) =703371954a(24) =1517066930a(25) =3211565746a(26) =6667672242a(27) =13848320690a(28) =28478053042a(29) =58811259570