A039111 Numbers whose base-9 representation has the same number of 7's and 8's.

0, 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 15, 18, 19, 20, 21, 22, 23, 24, 27, 28, 29, 30, 31, 32, 33, 36, 37, 38, 39, 40, 41, 42, 45, 46, 47, 48, 49, 50, 51, 54, 55, 56, 57, 58, 59, 60, 71, 79, 81, 82, 83, 84, 85, 86, 87, 90, 91, 92, 93, 94, 95, 96, 99, 100, 101, 102

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• easy

Crossrefs

Cf. A007095.

Programs

Mathematica

okQ[n_]:=Module[{idn9=IntegerDigits[n,9]},Count[idn9,7]==Count[idn9,8]]
Select[Range[0,110],okQ] (* Harvey P. Dale, Dec 14 2010 *)
Select[Range[0,120],DigitCount[#,9,7]==DigitCount[#,9,8]&] (* Harvey P. Dale, Nov 03 2024 *)