T(2n+5,n), array T as in A055216.

Terms

a(0) =1a(1) =7a(2) =36a(3) =157a(4) =625a(5) =2343a(6) =8427a(7) =29406a(8) =100296a(9) =336066a(10) =1110300a(11) =3626559a(12) =11734557a(13) =37673295a(14) =120150909a(15) =381040101a(16) =1202559732a(17) =3779328996a(18) =11833845967a(19) =36934571140a(20) =114947180946a(21) =356828242618