Number of binary strings of length n with no substrings equal to 0000, 0010, or 0100.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =13a(5) =22a(6) =39a(7) =70a(8) =124a(9) =217a(10) =381a(11) =672a(12) =1186a(13) =2090a(14) =3680a(15) =6482a(16) =11422a(17) =20127a(18) =35461a(19) =62474a(20) =110069a(21) =193930a(22) =341683a(23) =601999a(24) =1060637a(25) =1868700a(26) =3292407a(27) =5800790a(28) =10220220a(29) =18006665