a(n) = ((2*n+1)^8 - 1)/32.

Terms

a(0) =0a(1) =205a(2) =12207a(3) =180150a(4) =1345210a(5) =6698715a(6) =25491585a(7) =80090332a(8) =217992420a(9) =530736345a(10) =1181964355a(11) =2447218290a(12) =4768371582a(13) =8825923015a(14) =15632700405a(15) =26652844920a(16) =43950269320a(17) =70371105957a(18) =109764982935a(19) =167250289390a(20) =249528913410a(21) =365256258675a(22) =525472668457a(23) =744102708180