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A251057 Odd numbers n not congruent to 5 mod 6 such that for all k >= 1 the numbers n*4^k + 1 are composite. 2

%I

%S 66741,271129,308481,327739,436029,482719,575041,636921,934909,965431,

%T 1259541,1259779,1384059,1518781,1639459,1997589,2038371,2131099,

%U 2191531,2397951,2473929,2541601,2576089,2931991,2965569,3098059,3608251,3885579,3999399,4095859

%N Odd numbers n not congruent to 5 mod 6 such that for all k >= 1 the numbers n*4^k + 1 are composite.

%C A123159(4) = a(1).

%C a(n) is a SierpiƄski number if it is of the form 6*m + 1.

%Y Cf. A076336, A123159, A251757.

%K nonn

%O 1,1

%A _Arkadiusz Wesolowski_, Dec 15 2014

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Last modified November 11 15:59 EST 2019. Contains 329019 sequences. (Running on oeis4.)