a(n) = 4^n * n*(n+1).

Terms

a(0) =0a(1) =8a(2) =96a(3) =768a(4) =5120a(5) =30720a(6) =172032a(7) =917504a(8) =4718592a(9) =23592960a(10) =115343360a(11) =553648128a(12) =2617245696a(13) =12213813248a(14) =56371445760a(15) =257698037760