%I #52 Mar 19 2023 05:01:36
%S 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,
%T 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,
%U 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
%N Largest digit of n.
%C A095815(n) = n + a(n). - _Reinhard Zumkeller_, Aug 23 2011
%C a(A007088(n)) = 1, n > 0; a(A136399(n)) > 1. - _Reinhard Zumkeller_, Apr 25 2012
%C a(n) = 9 for almost all n. Sum_{n < x} a(n) = 9x + O(.956^x). - _Charles R Greathouse IV_, Oct 02 2013
%H Reinhard Zumkeller, <a href="/A054055/b054055.txt">Table of n, a(n) for n = 0..10000</a>
%e a(12)=2 because 1 < 2.
%p [seq(max(convert(n,base,10)),n=0..120)];
%t 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 *)
%t Max/@IntegerDigits[Range[0,110]] (* _Harvey P. Dale_, Apr 17 2016 *)
%o (Haskell)
%o a054055 = f 0 where
%o f m x | x <= 9 = max m x
%o | otherwise = f (max m d) x' where (x',d) = divMod x 10
%o -- _Reinhard Zumkeller_, Jun 20 2012, May 14 2011
%o (PARI) a(n)=vecmax(eval(Vec(Str(n)))) \\ _Charles R Greathouse IV_, Jun 16 2011
%o (PARI) a(n)=vecmax(digits(n)) \\ _Charles R Greathouse IV_, Oct 02 2013
%o (Magma) [n eq 0 select 0 else Maximum(Intseq(n)): n in [0..104]]; // _Bruno Berselli_, Aug 24 2011
%o (Python)
%o def A054055(n): return max(int(d) for d in str(n)) # _Chai Wah Wu_, Jun 06 2022
%Y For bases 3 through 12 see A190592, A190593, A190594, A190595, A190596, A190597, A190598, A054055, A190599, A190600.
%Y Cf. A054054.
%K base,easy,nonn,look
%O 0,3
%A _Henry Bottomley_, Apr 29 2000