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%I #24 Feb 21 2024 02:19:12
%S 19,79,1279,5119,20479,81919,1310719,21474836479,1407374883553279,
%T 90071992547409919,23611832414348226068479,
%U 1784059615882449851322857461811868920478433279
%N Primes of form 5*2^n-1.
%H Heiko Harborth, <a href="http://ami.ektf.hu/uploads/papers/finalpdf/AMI_41_from57to62.pdf">On h-perfect numbers</a>, Annales Mathematicae et Informaticae, 41 (2013) pp. 57-62.
%H <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a>
%F a(n) = 5*2^A001770(n) - 1. - _Max Alekseyev_, Feb 20 2024
%t Select[Table[5*2^n-1,{n,0,150}],PrimeQ] (* _Jean-François Alcover_, Mar 21 2011 *)
%Y See A001770 for more terms.
%K nonn,nice
%O 1,1
%A _N. J. A. Sloane_, Dec 29 1999
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