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Triangle read by rows: T(n,k) = least number m > 0 such that m^m contains exactly k distinct digits in base n, 1 <= k <= n, or 0 if no such m exists.
2

%I #19 Oct 14 2014 15:32:41

%S 1,1,2,1,3,5,1,2,3,6,1,5,3,6,11,1,3,4,10,7,9,1,3,4,8,5,10,9,1,4,5,0,7,

%T 10,17,13,1,3,4,0,7,18,15,11,16,1,3,4,5,7,14,9,11,13,19,1,3,4,5,6,0,

%U 10,9,14,17,16,1,3,4,5,8,9,10,18,23,17,15,27,1,3,4,0,6,26,9,15,14,11

%N Triangle read by rows: T(n,k) = least number m > 0 such that m^m contains exactly k distinct digits in base n, 1 <= k <= n, or 0 if no such m exists.

%e T(n,k) is given by (row n corresponds to base n):

%e 1;

%e 1, 2;

%e 1, 3, 5;

%e 1, 2, 3, 6;

%e 1, 5, 3, 6, 11;

%e 1, 3, 4, 10, 7, 9;

%e 1, 3, 4, 8, 5, 10, 9;

%e 1, 4, 5, 0, 7, 10, 17, 13;

%e 1, 3, 4, 0, 7, 18, 15, 11, 16;

%e 1, 3, 4, 5, 7, 14, 9, 11, 13, 19; (base 10)

%e 1, 3, 4, 5, 6, 0, 10, 9, 14, 17, 16;

%e 1, 3, 4, 5, 8, 9, 10, 18, 23, 17, 15, 27;

%e 1, 3, 4, 0, 6, 26, 9, 15, 14, 11, 16, 20, 19;

%e 1, 3, 5, 6, 8, 10, 9, 12, 42, 13, 18, 16, 22, 29;

%o (PARI)

%o a(n,b)=k=1;while(#vecsort(digits(k^k,b),,8)!=n,if(#digits(k^k)>100*n,return(0));k++);k

%o print1(1,", ");b=2;while(b<20,for(n=1,b,print1(a(n,b),", "));b++)

%K nonn,base,tabl

%O 1,3

%A _Derek Orr_, Sep 30 2014