Eighth column (k=7) of sextinomial array A063260.

Terms

a(0) =4a(1) =27a(2) =104a(3) =305a(4) =756a(5) =1667a(6) =3368a(7) =6354a(8) =11340a(9) =19327a(10) =31680a(11) =50219a(12) =77324a(13) =116055a(14) =170288a(15) =244868a(16) =345780a(17) =480339a(18) =657400a(19) =887589a(20) =1183556a(21) =1560251a(22) =2035224a(23) =2628950a(24) =3365180a(25) =4271319a(26) =5378832