Reduced A276850.

Terms

a(0) =1a(1) =-2a(2) =1a(3) =14a(4) =-14a(5) =1a(6) =2a(7) =-24a(8) =36a(9) =-8a(10) =-8a(11) =1a(12) =1a(13) =165a(14) =-330a(15) =135a(16) =90a(17) =-6a(18) =-36a(19) =-18a(20) =1a(21) =2a(22) =2a(23) =-286a(24) =715a(25) =-440a(26) =-220a(27) =55a(28) =165a(29) =55