Numbers of form 2^i*10^j, with i, j >= 0.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =10a(5) =16a(6) =20a(7) =32a(8) =40a(9) =64a(10) =80a(11) =100a(12) =128a(13) =160a(14) =200a(15) =256a(16) =320a(17) =400a(18) =512a(19) =640a(20) =800a(21) =1000a(22) =1024a(23) =1280a(24) =1600a(25) =2000a(26) =2048a(27) =2560a(28) =3200a(29) =4000