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 A178652 Primes of the form 4^k + 13^2. 1

%I

%S 173,233,1193,16553,262313,67109033,1073741993,4611686018427388073,

%T 73786976294838206633,19807040628566084398385987753,

%U 1361129467683753853853498429727072845993

%N Primes of the form 4^k + 13^2.

%C Necessarily k is odd, 4^2 + 13^2 a multiple of 5.

%e a(1) = 4^1 + 13^2 = 173.

%e a(2) = 4^3 + 13^2 = 233.

%e a(11) = 4^65 + 13^2 = 1361129467683753853853498429727072845993.

%e a(12) = 4^99 + 13^2 = 401734511064747568885490523085290650630550748445698208825513.

%t Select[4^Range[0,70]+13^2,PrimeQ] (* _Harvey P. Dale_, Mar 05 2015 *)

%o (PARI) forstep(n=1,999,2,if(ispseudoprime(t=4^n+169),print1(t", "))) \\ _Charles R Greathouse IV_, Aug 27 2013

%Y Cf. A176969, A176978, A177833.

%K nonn

%O 1,1

%A Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Jun 01 2010

%E New name from _Charles R Greathouse IV_, Aug 27 2013

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Last modified February 27 07:07 EST 2020. Contains 332300 sequences. (Running on oeis4.)