A039281 Numbers whose base-4 representation has the same nonzero number of 1's and 3's.

7, 13, 19, 27, 28, 30, 39, 45, 49, 52, 54, 57, 67, 75, 76, 78, 95, 99, 107, 108, 110, 112, 114, 119, 120, 122, 125, 135, 141, 147, 155, 156, 158, 167, 173, 177, 180, 182, 185, 193, 196, 198, 201, 208, 210, 215, 216, 218, 221, 225, 228, 230, 233, 245, 259, 267

Offset

1,1

Links

Table of n, a(n) for n=1..56.

Mathematica

Select[Range[300], DigitCount[#, 4, 1]==DigitCount[#, 4, 3]>0&] (* Harvey P. Dale, Apr 24 2019 *)

Crossrefs

Cf. A007090.

Sequence in context: A277093 A004082 A246294 * A045115 A331830 A221027

Adjacent sequences: A039278 A039279 A039280 * A039282 A039283 A039284

Keyword

nonn,base,easy

Author

Olivier Gérard

Status

approved