a(n) = sinh(2*arcsinh(n))^2 = 4*n^2*(n^2 + 1).

Terms

a(0) =0a(1) =8a(2) =80a(3) =360a(4) =1088a(5) =2600a(6) =5328a(7) =9800a(8) =16640a(9) =26568a(10) =40400a(11) =59048a(12) =83520a(13) =114920a(14) =154448a(15) =203400a(16) =263168a(17) =335240a(18) =421200a(19) =522728a(20) =641600a(21) =779688a(22) =938960a(23) =1121480a(24) =1329408a(25) =1565000a(26) =1830608a(27) =2128680a(28) =2461760a(29) =2832488