Triangle of characteristic polynomials, see Mathematica code.

Terms

a(0) =1a(1) =1a(2) =-1a(3) =4a(4) =-6a(5) =1a(6) =36a(7) =-62a(8) =20a(9) =-1a(10) =576a(11) =-1064a(12) =440a(13) =-50a(14) =1a(15) =14400a(16) =-27752a(17) =13092a(18) =-2068a(19) =105a(20) =-1a(21) =518400a(22) =-1027872a(23) =526240a(24) =-99568a(25) =7476a(26) =-196a(27) =1a(28) =25401600a(29) =-51402528