Duplicate of A014432.

Terms

a(0) =1a(1) =3a(2) =3a(3) =12a(4) =30a(5) =111a(6) =363a(7) =1353a(8) =4917a(9) =18777a(10) =71769a(11) =280506a(12) =1103556a(13) =4395009a(14) =17622309