G.f. A(x) satisfies A(x) = 1 / (1 - x * (1 + x + x^2 + x^3) * A(x^4)).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =16a(6) =32a(7) =64a(8) =128a(9) =257a(10) =515a(11) =1032a(12) =2068a(13) =4146a(14) =8310a(15) =16656a(16) =33384a(17) =66916a(18) =134125a(19) =268837a(20) =538850a(21) =1080064a(22) =2164860a(23) =4339204a(24) =8697416a(25) =17432944a(26) =34942268a(27) =70037629a(28) =140382111a(29) =281379296