Inverse of number triangle A(n,k) = 1/((10*10^n-1)/9) if k <= n <= 2k, 0 otherwise.

Terms

a(0) =1a(1) =0a(2) =11a(3) =0a(4) =-11a(5) =111a(6) =0a(7) =11a(8) =-111a(9) =1111a(10) =0a(11) =0a(12) =0a(13) =-1111a(14) =11111a(15) =0a(16) =-11a(17) =111a(18) =0a(19) =-11111a(20) =111111a(21) =0a(22) =0a(23) =0a(24) =0a(25) =0a(26) =-111111a(27) =1111111a(28) =0a(29) =11