A054055 Largest digit of n.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 2, 2, 3, 4, 5, 6, 7, 8, 9, 3, 3, 3, 3, 4, 5, 6, 7, 8, 9, 4, 4, 4, 4, 4, 5, 6, 7, 8, 9, 5, 5, 5, 5, 5, 5, 6, 7, 8, 9, 6, 6, 6, 6, 6, 6, 6, 7, 8, 9, 7, 7, 7, 7, 7, 7, 7, 7, 8, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 1, 1, 2, 3, 4

Offset: 0

Author

Henry Bottomley, Apr 29 2000

Keywords

• base
• easy
• nonn
• look

Comments

A095815(n) = n + a(n). - Reinhard Zumkeller, Aug 23 2011

a(A007088(n)) = 1, n > 0; a(A136399(n)) > 1. - Reinhard Zumkeller, Apr 25 2012

a(n) = 9 for almost all n. Sum_{n < x} a(n) = 9x + O(.956^x). - Charles R Greathouse IV, Oct 02 2013

Examples

			a(12)=2 because 1 < 2.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Crossrefs

For bases 3 through 12 see A190592, A190593, A190594, A190595, A190596, A190597, A190598, A054055, A190599, A190600.

Cf. A054054.

Programs

Haskell

a054055 = f 0 where
   f m x | x <= 9 = max m x
         | otherwise = f (max m d) x' where (x',d) = divMod x 10
-- Reinhard Zumkeller, Jun 20 2012, May 14 2011

Magma

[n eq 0 select 0 else Maximum(Intseq(n)): n in [0..104]]; // Bruno Berselli, Aug 24 2011

Maple

[seq(max(convert(n,base,10)),n=0..120)];

Mathematica

f[n_] := Sort[IntegerDigits[n]][[-1]]; Array[f, 105, 0] (* Alonso del Arte, May 14 2011 *) (* and revised by Robert G. Wilson v, Aug 24 2011 *)
Max/@IntegerDigits[Range[0,110]] (* Harvey P. Dale, Apr 17 2016 *)

PARI

a(n)=vecmax(eval(Vec(Str(n)))) \\ Charles R Greathouse IV, Jun 16 2011

PARI

a(n)=vecmax(digits(n)) \\ Charles R Greathouse IV, Oct 02 2013

Python

def A054055(n): return max(int(d) for d in str(n)) # Chai Wah Wu, Jun 06 2022