a(n) is the number of binary strings of length n such that there exist 4 or more ones in a subsequence of length 5 or less.

A130902

a(n) is the number of binary strings of length n such that there exist 4 or more ones in a subsequence of length 5 or less.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =6a(5) =16a(6) =39a(7) =91a(8) =207a(9) =463a(10) =1014a(11) =2188a(12) =4671a(13) =9888a(14) =20786a(15) =43435a(16) =90302a(17) =186934a(18) =385547a(19) =792642a(20) =1625035a(21) =3323393a(22) =6782041a(23) =13813588a(24) =28087444a(25) =57023945a(26) =115614136a(27) =234117510a(28) =473564782a(29) =956961354

External references