Binomial transform of A015128.

Terms

a(0) =1a(1) =3a(2) =9a(3) =27a(4) =79a(5) =225a(6) =627a(7) =1717a(8) =4633a(9) =12341a(10) =32501a(11) =84737a(12) =218959a(13) =561263a(14) =1428287a(15) =3610671a(16) =9072367a(17) =22668285a(18) =56345835a(19) =139382713a(20) =343242533a(21) =841713531a(22) =2055944117a(23) =5003148987a(24) =12132552115a(25) =29323810757a(26) =70651867863a(27) =169719163521a(28) =406541986857a(29) =971192810019