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%I #18 Dec 28 2014 23:45:42
%S 56169,651249,20985561,1054235961,1688470281,3718682361,3923393769,
%T 4013349201,5866487649,6557598441,7121165769,7232992209,8527229649,
%U 8764891641,9387865881,10441365489,12922915041,15279184881,17063935641,19501284609,19760206041
%N Odd perfect powers n not congruent to 1 mod 6 such that n*4^k - 1 has a covering set.
%C If a(n) is a square, then for all k >= 1 the numbers a(n)*4^k - 1 have at least three distinct prime factors.
%K nonn
%O 1,1
%A _Arkadiusz Wesolowski_, Dec 15 2014