Diagonal sums of the Riordan array (1-4*x+4*x^2, x*(1-2*x)) (A167431).

Terms

a(0) =1a(1) =-4a(2) =5a(3) =-6a(4) =13a(5) =-16a(6) =25a(7) =-42a(8) =57a(9) =-92a(10) =141a(11) =-206a(12) =325a(13) =-488a(14) =737a(15) =-1138a(16) =1713a(17) =-2612a(18) =3989a(19) =-6038a(20) =9213a(21) =-14016a(22) =21289a(23) =-32442a(24) =49321a(25) =-75020a(26) =114205a(27) =-173662a(28) =264245a(29) =-402072