Column 1 of triangle A118231.

Terms

a(0) =1a(1) =-2a(2) =-2a(3) =4a(4) =-2a(5) =2a(6) =4a(7) =-6a(8) =-4a(9) =6a(10) =-4a(11) =4a(12) =14a(13) =-14a(14) =-8a(15) =8a(16) =-16a(17) =18a(18) =8a(19) =-12a(20) =6a(21) =-6a(22) =-6a(23) =-10a(24) =28a(25) =-6a(26) =-10a(27) =4a(28) =-2a(29) =4