

A073531


Number of ndigit positive integers with all distinct digits.


4



9, 81, 648, 4536, 27216, 136080, 544320, 1632960, 3265920, 3265920, 0, 0, 0
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OFFSET

1,1


COMMENTS

For any base b the number of distinctdigit numbers is finite. For base 10, the maximal distinctdigit number is 9876543210; for any larger number at least two digits coincide. The number of distinctdigit primes is also finite, see A073532.
If "positive" is replaced by "nonnegative" we get the sequence 10, 81, 648, 4536, 27216, 136080, 544320, 1632960, 3265920, 3265920, 0, 0, 0, ...


LINKS

Table of n, a(n) for n=1..13.
Eric Weisstein's World of Mathematics, Digit


FORMULA

a(n) = 9*9!/(10n)!.


EXAMPLE

a(3)=648 because there are 648 threedigit integers with distinct digits.


MATHEMATICA

Table[9*9!/(10n)!, {n, 10}]


CROSSREFS

Cf. A073532.
Sequence in context: A272242 A206728 A206857 * A206694 A125910 A171283
Adjacent sequences: A073528 A073529 A073530 * A073532 A073533 A073534


KEYWORD

base,nonn


AUTHOR

Zak Seidov, Aug 29 2002


STATUS

approved



