Number of runs of 1's of length <= 3 over all binary strings of length n.

Terms

a(0) =0a(1) =1a(2) =3a(3) =8a(4) =19a(5) =45a(6) =104a(7) =236a(8) =528a(9) =1168a(10) =2560a(11) =5568a(12) =12032a(13) =25856a(14) =55296a(15) =117760a(16) =249856a(17) =528384a(18) =1114112a(19) =2342912a(20) =4915200a(21) =10289152a(22) =21495808a(23) =44826624a(24) =93323264a(25) =193986560a(26) =402653184a(27) =834666496a(28) =1728053248a(29) =3573547008