Central column of triangle A102427.

Terms

a(0) =1a(1) =3a(2) =6a(3) =28a(4) =55a(5) =286a(6) =560a(7) =3060a(8) =5985a(9) =33649a(10) =65780a(11) =376740a(12) =736281a(13) =4272048a(14) =8347680a(15) =48903492a(16) =95548245a(17) =563921995a(18) =1101716330a(19) =6540715896a(20) =12777711870a(21) =76223753060a(22) =148902215280a(23) =891794789340