Number of binary strings of length n with no substrings equal to 0101, 0110, or 1001.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =13a(5) =20a(6) =33a(7) =56a(8) =93a(9) =152a(10) =250a(11) =414a(12) =685a(13) =1130a(14) =1864a(15) =3078a(16) =5084a(17) =8394a(18) =13857a(19) =22878a(20) =37775a(21) =62370a(22) =102975a(23) =170016a(24) =280708a(25) =463468a(26) =765213a(27) =1263410a(28) =2085966a(29) =3444058