Number of length 8 primitive (=aperiodic or period 8) n-ary words.

Terms

a(0) =0a(1) =0a(2) =240a(3) =6480a(4) =65280a(5) =390000a(6) =1678320a(7) =5762400a(8) =16773120a(9) =43040160a(10) =99990000a(11) =214344240a(12) =429960960a(13) =815702160a(14) =1475750640a(15) =2562840000a(16) =4294901760a(17) =6975673920a(18) =11019855600a(19) =16983432720a(20) =25599840000a(21) =37822664880a(22) =54875639280a(23) =78310705440a(24) =110074982400