Monotonic ordering of nonnegative differences 4^i-10^j, for 40>=i>=0, j>=0.

Terms

a(0) =0a(1) =3a(2) =6a(3) =15a(4) =24a(5) =54a(6) =63a(7) =156a(8) =246a(9) =255a(10) =924a(11) =1014a(12) =1023a(13) =3096a(14) =3996a(15) =4086a(16) =4095a(17) =6384a(18) =15384a(19) =16284a(20) =16374a(21) =16383a(22) =48576a(23) =55536a(24) =64536a(25) =65436a(26) =65526a(27) =65535a(28) =162144a(29) =252144