Euler transform of composite numbers.

Terms

a(0) =1a(1) =4a(2) =16a(3) =52a(4) =157a(5) =434a(6) =1144a(7) =2862a(8) =6906a(9) =16090a(10) =36449a(11) =80430a(12) =173555a(13) =366802a(14) =761102a(15) =1552569a(16) =3118508a(17) =6174461a(18) =12064383a(19) =23283027a(20) =44419855a(21) =83834278a(22) =156626605a(23) =289839251a(24) =531534746a(25) =966483534a(26) =1743164649a(27) =3119864511a(28) =5543030861a(29) =9779552117