A039088 Numbers whose base-9 representation has the same number of 1's and 6's.

0, 2, 3, 4, 5, 7, 8, 15, 18, 20, 21, 22, 23, 25, 26, 27, 29, 30, 31, 32, 34, 35, 36, 38, 39, 40, 41, 43, 44, 45, 47, 48, 49, 50, 52, 53, 55, 63, 65, 66, 67, 68, 70, 71, 72, 74, 75, 76, 77, 79, 80, 87, 105, 114, 123, 132, 135, 137, 138, 139, 140, 142, 143, 150, 159, 162

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

filter:= proc(n) local L;
  L:= convert(n, base, 9);
  numboccur(1, L) = numboccur(6, L)
end proc:
select(filter, [$0..1000]); # Robert Israel, Mar 13 2018

Mathematica

Select[Range[0, 25427], DigitCount[#, 9, 1]==DigitCount[#, 9, 6]&] (* Chris R. Rehmann, Mar 10 2026 *)

Prog

(PARI) isok(n) = {my(d = digits(n, 9)); #select(x->(x==1), d) == #select(x->(x==6), d); } \\ Michel Marcus, Mar 13 2018
(MATLAB) x = 0:25427; d = dec2base(x, 9)-'0'; a = x(sum(d==1, 2)==sum(d==6, 2)); disp(regexprep(num2str(a), ' +', ', ')) % Chris R. Rehmann, Mar 10 2026

Crossrefs

Cf. A007095, A039369.

Cf. A039084, A039085, A039086, A039087, A039089, A039090.

Cf. A039082, A039094, A039099, A039103, A039106.

Sequence in context: A309880 A054762 A394543 * A111794 A030290 A099088

Adjacent sequences: A039085 A039086 A039087 * A039089 A039090 A039091

Keyword

nonn,base,easy

Author

Olivier Gérard

Status

approved