T(3,n) with T(n,m) as in A063394.

Terms

a(0) =1a(1) =15a(2) =47a(3) =131a(4) =343a(5) =863a(6) =2111a(7) =5055a(8) =11903a(9) =27647a(10) =63487a(11) =144383a(12) =325631a(13) =729087a(14) =1622015a(15) =3588095a(16) =7897087a(17) =17301503a(18) =37748735a(19) =82051071a(20) =177733631a(21) =383778815a(22) =826277887a(23) =1774190591a(24) =3800039423a(25) =8120172543a(26) =17314086911a(27) =36842766335a(28) =78248935423