a(n) = (12*n)^4.

Terms

a(0) =0a(1) =20736a(2) =331776a(3) =1679616a(4) =5308416a(5) =12960000a(6) =26873856a(7) =49787136a(8) =84934656a(9) =136048896a(10) =207360000a(11) =303595776a(12) =429981696a(13) =592240896a(14) =796594176a(15) =1049760000a(16) =1358954496a(17) =1731891456a(18) =2176782336a(19) =2702336256a(20) =3317760000a(21) =4032758016a(22) =4857532416a(23) =5802782976a(24) =6879707136a(25) =8100000000