Number of binary words of length n not containing the substrings 0000, 0001, 0011, 0111.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =12a(5) =20a(6) =32a(7) =48a(8) =76a(9) =116a(10) =176a(11) =272a(12) =412a(13) =628a(14) =960a(15) =1456a(16) =2220a(17) =3380a(18) =5136a(19) =7824a(20) =11900a(21) =18100a(22) =27552a(23) =41904a(24) =63756a(25) =97012a(26) =147568a(27) =224528a(28) =341596a(29) =519668