Erroneous version of A052218.

Terms

a(0) =4a(1) =13a(2) =40a(3) =130a(4) =400a(5) =1300a(6) =4000a(7) =13000a(8) =40000a(9) =130000a(10) =400000a(11) =1300000a(12) =4000000a(13) =13000000a(14) =40000000a(15) =130000000a(16) =400000000a(17) =1300000000a(18) =4000000000a(19) =13000000000a(20) =40000000000a(21) =130000000000a(22) =400000000000