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Numbers k such that 105*2^k+1 is prime.
1

%I #33 Apr 21 2022 03:26:34

%S 1,2,5,7,8,12,14,23,27,33,38,49,61,62,85,93,94,107,155,182,215,273,

%T 382,392,413,434,490,1631,3063,3331,3461,3619,4199,4298,5191,7967,

%U 8837,9589,10367,13700,14458,14821,21021,21409,22939,29927,30552,30840

%N Numbers k such that 105*2^k+1 is prime.

%H Jeppe Stig Nielsen, <a href="/A032402/b032402.txt">Table of n, a(n) for n = 1..78</a> (terms n = 1..74 from Robert Price)

%H Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a>

%H Ray Ballinger and Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a>

%H Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a>

%H Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a>

%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>

%o (PARI) is(n)=ispseudoprime(105*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn

%O 1,2

%A _James R. Buddenhagen_