T(n,n-3), array T as in A054120.

Terms

a(0) =1a(1) =9a(2) =39a(3) =114a(4) =261a(5) =507a(6) =879a(7) =1404a(8) =2109a(9) =3021a(10) =4167a(11) =5574a(12) =7269a(13) =9279a(14) =11631a(15) =14352a(16) =17469a(17) =21009a(18) =24999a(19) =29466a(20) =34437a(21) =39939a(22) =45999a(23) =52644a(24) =59901a(25) =67797a(26) =76359a(27) =85614a(28) =95589a(29) =106311