How many more primes than irreducible GF(2)[X] polynomials there are in range [0,2^n].

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =1a(5) =3a(6) =4a(7) =8a(8) =13a(9) =26a(10) =45a(11) =83a(12) =152a(13) =281a(14) =523a(15) =974a(16) =1822a(17) =3451a(18) =6490a(19) =12348a(20) =23389a(21) =44598a(22) =85076a(23) =162735a(24) =311721a(25) =598669a(26) =1150613a(27) =2215562a(28) =4271844a(29) =8247356