a(n) = n^8 - n^4 + 1.

Terms

a(0) =1a(1) =1a(2) =241a(3) =6481a(4) =65281a(5) =390001a(6) =1678321a(7) =5762401a(8) =16773121a(9) =43040161a(10) =99990001a(11) =214344241a(12) =429960961a(13) =815702161a(14) =1475750641a(15) =2562840001a(16) =4294901761a(17) =6975673921a(18) =11019855601a(19) =16983432721a(20) =25599840001a(21) =37822664881a(22) =54875639281a(23) =78310705441a(24) =110074982401