Triangle T(n, k) = A176013(n, k) + A176013(n, n-k+1), read by rows.

Terms

a(0) =-2a(1) =3a(2) =3a(3) =-7a(4) =-18a(5) =-7a(6) =25a(7) =96a(8) =96a(9) =25a(10) =-121a(11) =-650a(12) =-800a(13) =-650a(14) =-121a(15) =721a(16) =5490a(17) =7500a(18) =7500a(19) =5490a(20) =721a(21) =-5041a(22) =-53067a(23) =-92610a(24) =-73500a(25) =-92610a(26) =-53067a(27) =-5041a(28) =40321a(29) =564704