A043531 Number of distinct base-4 digits of n.

1, 1, 1, 2, 1, 2, 2, 2, 2, 1, 2, 2, 2, 2, 1, 2, 2, 3, 3, 2, 1, 2, 2, 3, 2, 2, 3, 3, 2, 3, 2, 2, 3, 2, 3, 3, 2, 2, 3, 2, 2, 1, 2, 3, 3, 2, 2, 2, 3, 3, 2, 3, 2, 3, 2, 3, 3, 2, 2, 2, 2, 2, 1, 2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 3, 4, 3, 3, 4, 3, 2, 2, 3, 3, 2, 1, 2, 2, 3, 2, 2

Offset

1,4

Links

Table of n, a(n) for n=1..90.

Mathematica

Table[Length[Union[IntegerDigits[n, 4]]], {n, 100}] (* Harvey P. Dale, Aug 25 2016 *)

Crossrefs

Cf. A007090.

Sequence in context: A275675 A219025 A270746 * A297772 A043556 A230643

Adjacent sequences: A043528 A043529 A043530 * A043532 A043533 A043534

Keyword

nonn,base

Author

Clark Kimberling

Status

approved