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COMMENTS
| a(10) = 987654103 = A007810(9). For n >= 3, a(n) < A062813(n), a multiple of n.
Contribution R. J. Mathar, May 15 2010 (START):
Supposed all digits are used and the digits at positions 0 to n-1 are d_0, d_1,... d_{n-1}, the candidates are d_0+d_1*n+d_2*n^2+....+d_{n-1}*n^(n-1).
These values are (n-1)*n/2 (mod n-1), and they cannot be prime if n is even, because this number is = 0 (mod n-1) then, showing that n-1 is a divisor.
In conclusion, if n is even, the entries have at most n-1 digits in base n , which
yields a(11) >= 25678048763, a(12) = 736867805209, a(13) >= 23136292864193,
a(14) = 789018236128391, a(15) >= 29043982525257901, a(16) = 1147797409030815779. (END)
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