N is a seven digit base-14 positive integer using the digits 1 to 7 exactly once.
Determine the total number of value(s) of N that are divisible by the base-14 number 16.
So, the last 2 digits are limited to {12,32,52,72,16,36,56,76}
Within the first 5 digits:
1,4,6 add + or - 4 to the mod value (depending on position)
2,3,7 add + or - 8 to the mod value
5 adds 0 to the mod value
1 and 6 are interchangeable and 2 and 7 are interchangeable.
Examples found so far:
5146372
5641372
1457236
1452736
I suspect there are a dozen more or so maybe twice that
Edited on September 12, 2010, 2:33 pm
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Posted by Larry
on 2010-09-12 14:22:24 |