a(n) = Numerator of (0 followed by 1's) - n/2^n.

Terms

a(0) =0a(1) =1a(2) =1a(3) =5a(4) =3a(5) =27a(6) =29a(7) =121a(8) =31a(9) =503a(10) =507a(11) =2037a(12) =1021a(13) =8179a(14) =8185a(15) =32753a(16) =4095a(17) =131055a(18) =131063a(19) =524269a(20) =262139a(21) =2097131a(22) =2097141a(23) =8388585a(24) =2097149a(25) =33554407a(26) =33554419a(27) =134217701a(28) =67108857a(29) =536870883