Monotonic ordering of nonnegative differences 4^i-9^j, for 40>= i>=0, j>=0.

Terms

a(0) =0a(1) =3a(2) =7a(3) =15a(4) =55a(5) =63a(6) =175a(7) =247a(8) =255a(9) =295a(10) =943a(11) =1015a(12) =1023a(13) =3367a(14) =4015a(15) =4087a(16) =4095a(17) =6487a(18) =9823a(19) =15655a(20) =16303a(21) =16375a(22) =16383a(23) =58975a(24) =64807a(25) =65455a(26) =65527a(27) =65535a(28) =203095a(29) =255583