[seqfan] Re: Counting problem
Harvey P. Dale
hpd1 at nyu.edu
Wed Jun 17 21:57:09 CEST 2009
Is the answer always 1? The numbers satisfying your conditions,
starting with n=1, are 5, 75, 375, 9375, 59375, 359375, and 3359375.
Note that once any such number is found, the number for the next higher
n has the same ending digits with a prepended different odd digit.
From: seqfan-bounces at list.seqfan.eu
[mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of David Wilson
Sent: Tuesday, June 16, 2009 11:22 PM
To: Sequence Fans
Subject: [seqfan] Counting problem
How many n-digit numbers with all odd digits are divisible by 5^n?
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