Signed Delannoy triangle convolved with 10^n.

Terms

a(0) =1a(1) =10a(2) =-1a(3) =100a(4) =-30a(5) =1a(6) =1000a(7) =-500a(8) =50a(9) =-1a(10) =10000a(11) =-7000a(12) =1300a(13) =-70a(14) =1a(15) =100000a(16) =-90000a(17) =25000a(18) =-2500a(19) =90a(20) =-1a(21) =1000000a(22) =-1100000a(23) =410000a(24) =-63000a(25) =4100a(26) =-110a(27) =1a(28) =10000000a(29) =-13000000