a(n) = prime(n) * 2^n.

Terms

a(0) =4a(1) =12a(2) =40a(3) =112a(4) =352a(5) =832a(6) =2176a(7) =4864a(8) =11776a(9) =29696a(10) =63488a(11) =151552a(12) =335872a(13) =704512a(14) =1540096a(15) =3473408a(16) =7733248a(17) =15990784a(18) =35127296a(19) =74448896a(20) =153092096a(21) =331350016a(22) =696254464a(23) =1493172224a(24) =3254779904a(25) =6777995264a(26) =13824425984a(27) =28722593792a(28) =58518929408a(29) =121332826112