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

Terms

a(0) =0a(1) =2a(2) =16a(3) =72a(4) =256a(5) =800a(6) =2304a(7) =6272a(8) =16384a(9) =41472a(10) =102400a(11) =247808a(12) =589824a(13) =1384448a(14) =3211264a(15) =7372800a(16) =16777216a(17) =37879808a(18) =84934656a(19) =189267968a(20) =419430400a(21) =924844032a(22) =2030043136a(23) =4437573632a(24) =9663676416a(25) =20971520000a(26) =45365592064a(27) =97844723712a(28) =210453397504