a(n) = n^6 - n^3 + 1.

Terms

a(0) =1a(1) =1a(2) =57a(3) =703a(4) =4033a(5) =15501a(6) =46441a(7) =117307a(8) =261633a(9) =530713a(10) =999001a(11) =1770231a(12) =2984257a(13) =4824613a(14) =7526793a(15) =11387251a(16) =16773121a(17) =24132657a(18) =34006393a(19) =47039023a(20) =63992001a(21) =85756861a(22) =113369257a(23) =148023723a(24) =191089153a(25) =244125001a(26) =308898201a(27) =387400807a(28) =481868353a(29) =594798933