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a(n) is the least k > 1 such that sum_{i = 1..n} k^(A003418(n)/i) is divisible by n.
1

%I #3 Mar 31 2012 13:20:57

%S 2,2,3,2,2,3,7,2,3,2,3,4,4,7,6,2,12,3,19,2,7,11,23,4,5,5,3,8,29,6,28,

%T 2,7,12,8,6,7,19,4,6,41,7,43,12,6,4,15,4,7,5,6,4,15,3,5,8,19,11,4,6,

%U 61,31,7,2,13,3,62,8,10,7,71,4,34,8,10,17,22,13,64,2,3,18,47,21,17,12,18,6,89

%N a(n) is the least k > 1 such that sum_{i = 1..n} k^(A003418(n)/i) is divisible by n.

%e a(3) = 3 because 2^6+2^3+2^2 = 76 is not divisible by 3, but 3^6+3^3+3^2 = 765 is.

%o (PARI) b = 1; for (n = 1, 100, b = lcm(b, n); k = 2; while (sum(i = 1, n, Mod(k, n)^(b/i)) != Mod(0, n), k++); print(k));

%Y Cf. A087313.

%K easy,nonn,less

%O 1,1

%A _David Wasserman_, May 02 2005