a(n) = A120963(n)/2.

Terms

a(0) =1a(1) =3a(2) =5a(3) =12a(4) =19a(5) =39a(6) =59a(7) =112a(8) =165a(9) =292a(10) =419a(11) =710a(12) =1001a(13) =1629a(14) =2257a(15) =3567a(16) =4877a(17) =7505a(18) =10133a(19) =15266a(20) =20399a(21) =30140a(22) =39881a(23) =57983a(24) =76085a(25) =108981a(26) =141877a(27) =200625a(28) =259373a(29) =362433