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

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =4a(7) =7a(8) =11a(9) =17a(10) =32a(11) =66a(12) =132a(13) =247a(14) =463a(15) =937a(16) =2001a(17) =4248a(18) =8758a(19) =18166a(20) =39181a(21) =87096a(22) =193493a(23) =425468a(24) =942610a(25) =2137196a(26) =4930702a(27) =11393809a(28) =26280211a(29) =61089849