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A032489 Numbers k such that 225*2^k+1 is prime. 1


%S 3,6,8,9,12,13,14,19,22,32,35,37,80,86,102,118,135,159,205,269,430,

%T 435,535,547,830,1020,1030,1079,1089,1112,1189,2244,2397,4497,5888,

%U 9549,15942,16855,19736,21936,26744,26926,36744,51142,53155,53532,67017,116067

%N Numbers k such that 225*2^k+1 is prime.

%H Jeppe Stig Nielsen, <a href="/A032489/b032489.txt">Table of n, a(n) for n = 1..69</a> (terms n = 1..67 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 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>

%t Select[Range[1000], PrimeQ[225*2^# + 1] & ] (* _Robert Price_, Dec 19 2018 *)

%o (PARI) is(n)=ispseudoprime(225*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn,hard

%O 1,1

%A _N. J. A. Sloane_.

%E a(47)-a(67) from the Ray Ballinger and Wilfrid Keller link by _Robert Price_, Dec 19 2018

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Last modified July 14 10:35 EDT 2020. Contains 335722 sequences. (Running on oeis4.)