Number of binary words of length n such that there is at least one 0 and every run of consecutive 0's is of length >= 4.

A209231

Number of binary words of length n such that there is at least one 0 and every run of consecutive 0's is of length >= 4.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =3a(6) =6a(7) =10a(8) =15a(9) =22a(10) =33a(11) =51a(12) =80a(13) =125a(14) =193a(15) =295a(16) =449a(17) =684a(18) =1045a(19) =1600a(20) =2451a(21) =3752a(22) =5738a(23) =8770a(24) =13403a(25) =20488a(26) =31326a(27) =47903a(28) =73251a(29) =112003

External references