a(n) is the number of binary strings of length n such that there exist 3 or more ones in a subsequence of length 5 or less.

A131283

a(n) is the number of binary strings of length n such that there exist 3 or more ones in a subsequence of length 5 or less.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =5a(4) =16a(5) =38a(6) =85a(7) =185a(8) =396a(9) =838a(10) =1748a(11) =3609a(12) =7400a(13) =15097a(14) =30681a(15) =62154a(16) =125588a(17) =253246a(18) =509850a(19) =1025153a(20) =2059159a(21) =4132679a(22) =8288643a(23) =16615051a(24) =33291367a(25) =66682128a(26) =133525499a(27) =267312553a(28) =535049374a(29) =1070786975

External references