a(n) = (2*n)^4.

Terms

a(0) =0a(1) =16a(2) =256a(3) =1296a(4) =4096a(5) =10000a(6) =20736a(7) =38416a(8) =65536a(9) =104976a(10) =160000a(11) =234256a(12) =331776a(13) =456976a(14) =614656a(15) =810000a(16) =1048576a(17) =1336336a(18) =1679616a(19) =2085136a(20) =2560000a(21) =3111696a(22) =3748096a(23) =4477456a(24) =5308416a(25) =6250000a(26) =7311616a(27) =8503056a(28) =9834496a(29) =11316496