Column 8 of triangle A055898.

Terms

a(0) =1a(1) =17a(2) =181a(3) =1361a(4) =8107a(5) =40187a(6) =172207a(7) =653921a(8) =2243296a(9) =7053912a(10) =20568960a(11) =56141388a(12) =144540144a(13) =353269224a(14) =824102928a(15) =1843357923a(16) =3969216603a(17) =8255612079a(18) =16635486439a(19) =32560881353a(20) =62048339353a(21) =115351334813