Number of binary strings of length n with no substrings equal to 0000, 0010, or 0111.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =13a(5) =21a(6) =33a(7) =52a(8) =81a(9) =125a(10) =193a(11) =297a(12) =457a(13) =702a(14) =1078a(15) =1655a(16) =2540a(17) =3898a(18) =5981a(19) =9177a(20) =14080a(21) =21602a(22) =33142a(23) =50846a(24) =78007a(25) =119676a(26) =183603a(27) =281677a(28) =432138a(29) =662969