Square array read by antidiagonals: T(n,k) = (k*(2*k+3)^n + 1)/(k+1).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =1a(6) =1a(7) =5a(8) =13a(9) =1a(10) =1a(11) =7a(12) =33a(13) =63a(14) =1a(15) =1a(16) =9a(17) =61a(18) =229a(19) =313a(20) =1a(21) =1a(22) =11a(23) =97a(24) =547a(25) =1601a(26) =1563a(27) =1a(28) =1a(29) =13