Number of binary strings of length n with no substrings equal to 0000, 0011, or 1011.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =13a(5) =21a(6) =33a(7) =50a(8) =75a(9) =112a(10) =166a(11) =245a(12) =361a(13) =531a(14) =780a(15) =1145a(16) =1680a(17) =2464a(18) =3613a(19) =5297a(20) =7765a(21) =11382a(22) =16683a(23) =24452a(24) =35838a(25) =52525a(26) =76981a(27) =112823a(28) =165352a(29) =242337