T(2n+3,n), array T as in A055794.

Terms

a(0) =1a(1) =5a(2) =16a(3) =42a(4) =98a(5) =210a(6) =420a(7) =792a(8) =1419a(9) =2431a(10) =4004a(11) =6370a(12) =9828a(13) =14756a(14) =21624a(15) =31008a(16) =43605a(17) =60249a(18) =81928a(19) =109802a(20) =145222a(21) =189750a(22) =245180a(23) =313560a(24) =397215a(25) =498771a(26) =621180a(27) =767746a(28) =942152a(29) =1148488