A039276 Numbers whose base-3 representation has the same nonzero number of 0's and 2's.

6, 11, 15, 19, 21, 32, 34, 38, 42, 46, 48, 56, 58, 60, 64, 66, 72, 89, 95, 97, 101, 103, 105, 113, 115, 119, 123, 127, 129, 137, 139, 141, 145, 147, 153, 167, 169, 173, 175, 177, 181, 183, 191, 193, 195, 199, 201, 207, 217, 219, 225, 260, 266, 268, 278, 284

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• easy

Crossrefs

Supersequence of A044995.

Cf. A007089, A005823.

Programs

Mathematica

Select[Range[300],DigitCount[#,3,0]==DigitCount[#,3,2]>0&] (* Harvey P. Dale, May 10 2011 *)

Python

from sympy.ntheory import count_digits
def ok(n): d = count_digits(n, 3); return 0 in d and 2 in d and d[0] == d[2]
print(list(filter(ok, range(285)))) # Michael S. Branicky, Jun 11 2021