No subject

[N. J. A. Sloane]

 From rcs at baskerville.CS.Arizona.EDU  Fri Nov 20 16:57:07 1998
Return-Path: <rcs at baskerville.CS.Arizona.EDU>
Date: Fri, 20 Nov 1998 22:54:50 +0100 (MET)
From: Dylan Thurston <Dylan.Thurston at math.unige.ch>
Subject: Re: kakmem 56
In-reply-to: <199811202131.QAA13226 at fry.research.att.com>
To: "N. J. A. Sloane" <njas at research.att.com>
Cc: math-fun at optima.CS.Arizona.EDU, eww6n at astsun.astro.virginia.edu,
        njas at research.att.com
Message-id: <Pine.SOL.3.91.981120224840.26949B-100000 at matsun16>
MIME-version: 1.0
Content-type: TEXT/PLAIN; charset=US-ASCII
Status: R

N. J. A. Sloane asks:
> ...
>  N     MAX L     DISTINCT
>  2       4           54
>  3       5          219
>  4       6          714
>  5       7        2,001
>  6       7        5,004
>  7       8       11,439
>  8       9       24,309
>  9       9       48,619
> 10      10       92,377
> 11      10      167.959
> 12      10      293,929
>  ...
> The second column is clear:  the greatest mutiplicative
> persistence of any n-digit number (e.g. 0, 77, 679
> have m.p. 0, 4, 5)
>  ...
> But what does the third column represent?  Neither Eric Weisstein or I can
> figure it out.

It is (10+n-1 choose n)-1, the number of choices of the n digits (except
for all zeros, which cannot be the digits of an n-digit number). 

--Dylan
  thurston at math.unige.ch