A signed triangle of V. I. Arnold for the Springer numbers (A001586).

Terms

a(0) =1a(1) =1a(2) =0a(3) =-2a(4) =-3a(5) =-3a(6) =-8a(7) =-6a(8) =-3a(9) =0a(10) =40a(11) =48a(12) =54a(13) =57a(14) =57a(15) =256a(16) =216a(17) =168a(18) =114a(19) =57a(20) =0a(21) =-1952a(22) =-2208a(23) =-2424a(24) =-2592a(25) =-2706a(26) =-2763a(27) =-2763a(28) =-17408a(29) =-15456