n written in fractional base 7/4.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =40a(8) =41a(9) =42a(10) =43a(11) =44a(12) =45a(13) =46a(14) =410a(15) =411a(16) =412a(17) =413a(18) =414a(19) =415a(20) =416a(21) =450a(22) =451a(23) =452a(24) =453a(25) =454a(26) =455a(27) =456a(28) =4120a(29) =4121