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A242788

Numbers n such that (n^n-3)/(n-3) is an integer.

1, 2, 4, 5, 6, 7, 9, 11, 13, 15, 16, 27, 31, 33, 36, 55, 73, 91, 133, 241, 249, 366, 367, 491, 513, 577, 733, 757, 871, 913, 971, 991, 1233, 1333, 1576, 1711, 1927, 2071, 2346, 2593, 2731, 3307, 3391, 3529, 4005, 4591, 5113, 5371, 5409, 5671, 5793, 6567, 6801, 7465, 7591

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OFFSET

1,2

COMMENTS

For n > 6, equivalent to n such that n^n = 3 mod n-3. - Chai Wah Wu, Jan 19 2015

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..4388

EXAMPLE

(6^6-3)/(6-3) = 46653/3 = 15551 is an integer. Thus 6 is a member of this sequence.

MATHEMATICA

Select[ Range@ 7600, Mod[ PowerMod[#, #, # - 3] - 3, # - 3] == 0 &] (* Robert G. Wilson v, Jan 21 2015 *)

PROG