A037904 Greatest digit of n - least digit of n.

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

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• nice

Comments

a(n) = A054055(n)-A054054(n); a(A010785(n)) = 0; for k>0: a(n) = a(n*10^k + A000030(n)) = a(n*10^k + A010879(n)) = a(n*10^k + A054054(n)) = a(n*10^k + A054055(n)) . - Reinhard Zumkeller, Dec 14 2007; corrected by David Wasserman, May 21 2008

Links

• R. Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A040163, A064834.

Programs

Haskell

a037904 = f 9 0 where
   f u v 0 = v - u
   f u v z = f (min u d) (max v d) z' where (z', d) = divMod z 10
-- Reinhard Zumkeller, Dec 16 2013

Maple

f:= n -> (max-min)(convert(n,base,10)):
map(f, [$1..1000]); # Robert Israel, Jul 07 2016

Mathematica

f[n_] := Block[{d = IntegerDigits[n]}, Max[d] - Min[d]]; Table[ f[n], {n, 1, 15}]

PARI

a(n)=my(d=digits(n)); vecmax(d)-vecmin(d) \\ Charles R Greathouse IV, Feb 07 2017

Python

def A037904(n): return int(max(s:=str(n)))-int(min(s)) # Chai Wah Wu, Nov 10 2023

Extensions

Incorrect comments deleted by Robert Israel, Jul 07 2016