p-INVERT of the positive integers, where p(S) = 1 - 3*S + 2*S^2.

Terms

a(0) =3a(1) =13a(2) =52a(3) =203a(4) =781a(5) =2976a(6) =11267a(7) =42469a(8) =159596a(9) =598499a(10) =2241165a(11) =8383872a(12) =31340691a(13) =117100285a(14) =437378260a(15) =1633244795a(16) =6097779229a(17) =22763575008a(18) =84971451155a(19) =317161317781