Number of ways writing 2^n as a sum of two nonprime numbers.

Terms

a(0) =1a(1) =0a(2) =1a(3) =4a(4) =7a(5) =19a(6) =36a(7) =82a(8) =170a(9) =362a(10) =740a(11) =1537a(12) =3144a(13) =6443a(14) =13116a(15) =26661a(16) =54034a(17) =109386a(18) =221121a(19) =446502a(20) =900436a(21) =1814910a(22) =3655069a(23) =7356483a(24) =14796994a(25) =29750473a(26) =59789057a(27) =120112121a(28) =241218391a(29) =484287995