a(n) = (6*n + 4)^4.

Terms

a(0) =256a(1) =10000a(2) =65536a(3) =234256a(4) =614656a(5) =1336336a(6) =2560000a(7) =4477456a(8) =7311616a(9) =11316496a(10) =16777216a(11) =24010000a(12) =33362176a(13) =45212176a(14) =59969536a(15) =78074896a(16) =100000000a(17) =126247696a(18) =157351936a(19) =193877776a(20) =236421376a(21) =285610000a(22) =342102016a(23) =406586896a(24) =479785216a(25) =562448656a(26) =655360000