4-step Fibonacci sequence starting with 1, 1, 0, 1.

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =3a(5) =5a(6) =9a(7) =18a(8) =35a(9) =67a(10) =129a(11) =249a(12) =480a(13) =925a(14) =1783a(15) =3437a(16) =6625a(17) =12770a(18) =24615a(19) =47447a(20) =91457a(21) =176289a(22) =339808a(23) =655001a(24) =1262555a(25) =2433653a(26) =4691017a(27) =9042226a(28) =17429451a(29) =33596347