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%I #11 Oct 08 2016 16:55:49
%S 2,5,7,34,195,727,3724,9124,92115,338161,2780514,6871290,99000993
%N Least k such that any sufficiently long repunit multiplied by k is a pandigital number in numerical base n.
%C Trailing terms of rows of A277055.
%C Written in base n, the terms read: 10, 12, 13, 114, 523, 2056, 7214, 13457, 92115, 21107A, B21116, 156776A, D211117, ...
%F Conjecture: for even n>4, a(n) = (n-2)*n^(n/2-1) + n^(n/2-2) + (n^(n/2)-1)/(n-1) + n/2 - 1.
%e Any binary repunit multiplied by 2 is a binary pandigital, so a(2)=2 (10 in binary).
%e k-th decimal repunit for k>4 multiplied by 92115 gives a decimal pandigital number (see A277054) with no number less than 92115 having the same property, so a(10)=92115.
%Y Cf. A002275, A171102, A277054, A277055, A277059.
%K nonn,base,more
%O 2,1
%A _Andrey Zabolotskiy_ and _Altug Alkan_, Sep 26 2016
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