T(n,3) diagonal of triangle in A095693.

Terms

a(0) =1a(1) =22a(2) =130a(3) =485a(4) =1400a(5) =3416a(6) =7392a(7) =14610a(8) =26895a(9) =46750a(10) =77506a(11) =123487a(12) =190190a(13) =284480a(14) =414800a(15) =591396a(16) =826557a(17) =1134870a(18) =1533490a(19) =2042425a(20) =2684836a(21) =3487352a(22) =4480400a(23) =5698550a(24) =7180875a(25) =8971326a(26) =11119122a(27) =13679155a(28) =16712410a(29) =20286400