a(n) = 10^n + 10*n.

Terms

a(0) =1a(1) =20a(2) =120a(3) =1030a(4) =10040a(5) =100050a(6) =1000060a(7) =10000070a(8) =100000080a(9) =1000000090a(10) =10000000100a(11) =100000000110