A043536 Number of distinct base-9 digits of n.

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

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Examples

			As 731 = 1*(9^3) + 0*(9^2) + 0*(9^1) + 2*(9^0), it is written in base 9 (A007095) as "1002". There are three kinds of digits present, thus a(731) = 3. - _Antti Karttunen_, Dec 22 2017
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..66430

Crossrefs

Cf. A007095, A043283, A044931, A044940, A044949.

Programs

Mathematica

Table[Count[DigitCount[n,9],+?(#>0&)],{n,100}] (* _Harvey P. Dale, Apr 30 2015 *)

PARI

A043536(n) = length(vecsort(digits(n,9),,8)); \\ Antti Karttunen, Dec 22 2017

Extensions

More terms from Antti Karttunen, Dec 22 2017