A106441 a(n) is the least k > 1 such that sum_{i = 1..n} k^(A003418(n)/i) is divisible by n.

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, 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, 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

Offset

1,1

Links

Table of n, a(n) for n=1..89.

Example

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.

Prog

(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));

Crossrefs

Cf. A087313.

Sequence in context: A138143 A285727 A281908 * A131836 A133829 A364925

Adjacent sequences: A106438 A106439 A106440 * A106442 A106443 A106444

Keyword

easy,nonn,less

Author

David Wasserman, May 02 2005

Status

approved