Diagonal sums of Riordan array (1-x-x^2,x(1-x)).

Terms

a(0) =1a(1) =-1a(2) =0a(3) =-2a(4) =1a(5) =-2a(6) =3a(7) =-3a(8) =5a(9) =-6a(10) =8a(11) =-11a(12) =14a(13) =-19a(14) =25a(15) =-33a(16) =44a(17) =-58a(18) =77a(19) =-102a(20) =135a(21) =-179a(22) =237a(23) =-314a(24) =416a(25) =-551a(26) =730a(27) =-967a(28) =1281a(29) =-1697