a(n) is the sum of prime numbers between 2^n+1 and 2^(n+1).

Terms

a(0) =2a(1) =3a(2) =12a(3) =24a(4) =119a(5) =341a(6) =1219a(7) =4361a(8) =16467a(9) =57641a(10) =208987a(11) =780915a(12) =2838550a(13) =10676000a(14) =39472122a(15) =148231324a(16) =559305605a(17) =2106222351a(18) =7995067942a(19) =30299372141a(20) =115430379568a(21) =440354051430