Binomial transform of A001037.

Terms

a(0) =1a(1) =3a(2) =6a(3) =12a(4) =26a(5) =62a(6) =158a(7) =418a(8) =1129a(9) =3087a(10) =8507a(11) =23573a(12) =65611a(13) =183333a(14) =514137a(15) =1446723a(16) =4083725a(17) =11560877a(18) =32816588a(19) =93385330a(20) =266360509a(21) =761373941a(22) =2180721568a(23) =6257750542a(24) =17988623409a(25) =51795127277a(26) =149363509694a(27) =431341949970