p-INVERT of the odd positive integers, where p(S) = (1 - S)^2.

Terms

a(0) =2a(1) =9a(2) =32a(3) =112a(4) =384a(5) =1296a(6) =4320a(7) =14256a(8) =46656a(9) =151632a(10) =489888a(11) =1574640a(12) =5038848a(13) =16061328a(14) =51018336a(15) =161558064a(16) =510183360a(17) =1607077584a(18) =5050815264a(19) =15841193328a(20) =49589822592a(21) =154968195600a(22) =483500770272