A scaled Legendre triangle.

Terms

a(0) =1a(1) =0a(2) =1a(3) =-2a(4) =2a(5) =1a(6) =0a(7) =4a(8) =4a(9) =1a(10) =6a(11) =8a(12) =22a(13) =6a(14) =1a(15) =0a(16) =16a(17) =136a(18) =52a(19) =8a(20) =1a(21) =-20a(22) =32a(23) =886a(24) =504a(25) =94a(26) =10a(27) =1a(28) =0a(29) =64