
1, 1, 1, 1, 2, 3, 3, 3, 4, 5, 5, 6, 6, 5, 6, 7, 5, 9, 8, 8, 9, 7, 7, 10, 9, 8, 9, 10, 8, 9, 9, 10, 9, 10, 10, 10, 10, 10, 9, 10, 10, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,5


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000
Index entries for sequences related to factorial numbers.


FORMULA

a(n) = A043537(A000142(n)).
a(n) < 10 iff A137579(n) = 0.
a(A182049(n)) < 10.  Reinhard Zumkeller, Apr 08 2012


EXAMPLE

n=12: 12! = 479001600 => a(12) = #{0,1,4,6,7,9} = 6.


MATHEMATICA

Map[Length[Union[IntegerDigits[#]]] &, Table[n!, {n, 0, 79}]] (* Geoffrey Critzer, May 25 2013 *)


PROG

(Haskell)
import Data.List (nub, sort)
a137580 = length . nub . show . a000142
 Reinhard Zumkeller, Apr 08 2012
(PARI) A137580(n)=#Set(digits(n!)) \\ M. F. Hasler, May 04 2015


CROSSREFS

Cf. A137577, A137578.
Cf. A034886.
Sequence in context: A049206 A194247 A084767 * A196369 A245710 A137512
Adjacent sequences: A137577 A137578 A137579 * A137581 A137582 A137583


KEYWORD

nonn,base


AUTHOR

Reinhard Zumkeller, Jan 27 2008


STATUS

approved

