a(n) is the number of binary strings of length n such that no subsequence of length 5 or less contains 3 or more ones.

A120118

a(n) is the number of binary strings of length n such that no subsequence of length 5 or less contains 3 or more ones.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =7a(4) =11a(5) =16a(6) =26a(7) =43a(8) =71a(9) =116a(10) =186a(11) =300a(12) =487a(13) =792a(14) =1287a(15) =2087a(16) =3382a(17) =5484a(18) =8898a(19) =14438a(20) =23423a(21) =37993a(22) =61625a(23) =99965a(24) =162165a(25) =263065a(26) =426736a(27) =692229a(28) =1122903a(29) =1821538

External references