Chapman's "evil" determinants I.

Terms

a(0) =1a(1) =-2a(2) =1a(3) =1a(4) =-18a(5) =-4a(6) =1a(7) =1a(8) =-70a(9) =1a(10) =-882a(11) =-32a(12) =1a(13) =1a(14) =-182a(15) =1a(16) =-29718a(17) =1a(18) =1a(19) =-1068a(20) =1a(21) =1a(22) =-500a(23) =-5604a(24) =-4030a(25) =1a(26) =1a(27) =-8890182a(28) =-776a(29) =1