Binomial transform of A004111.

Terms

a(0) =0a(1) =1a(2) =3a(3) =7a(4) =16a(5) =38a(6) =95a(7) =250a(8) =689a(9) =1972a(10) =5809a(11) =17484a(12) =53497a(13) =165845a(14) =519681a(15) =1643112a(16) =5234728a(17) =16785774a(18) =54128870a(19) =175409177a(20) =570906174a(21) =1865364061a(22) =6116175260a(23) =20117351296a(24) =66361157675a(25) =219484396545a(26) =727692105683