A031461 Numbers whose base-4 representation has the same number of 0's as 3's.

1, 2, 5, 6, 9, 10, 12, 19, 21, 22, 25, 26, 28, 35, 37, 38, 41, 42, 44, 49, 50, 52, 56, 71, 75, 77, 78, 83, 85, 86, 89, 90, 92, 99, 101, 102, 105, 106, 108, 113, 114, 116, 120, 135, 139, 141, 142, 147, 149, 150, 153, 154, 156, 163, 165

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Comments

Union of A031443 and A031448, i.e., numbers k in binary where the difference between numbers of 1's and 0's [A000120(k) - A023416(k) = -A037861(k)] is 1 or 0. - Henry Bottomley, Mar 02 2001

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000120, A007090, A023416, A031443, A031448, A037861.

Programs

Mathematica

Select[Range[165], Equal @@ DigitCount[#, 4, {0, 3}] &] (* Amiram Eldar, Aug 03 2023 *)