Sixth column of triangle A055584.

Terms

a(0) =1a(1) =10a(2) =59a(3) =268a(4) =1037a(5) =3598a(6) =11535a(7) =34832a(8) =100369a(9) =278546a(10) =749587a(11) =1966100a(12) =5046293a(13) =12714006a(14) =31522839a(15) =77070360a(16) =186122265a(17) =444596250a(18) =1051721755a(19) =2466250780a(20) =5737807901a(21) =13254000670a(22) =30417092639a(23) =69390565408