A053353 - OEIS

%I #35 Dec 21 2024 03:05:11

%S 1,2,5,10,13,40,41,45,56,64,72,86,94,121,160,213,338,352,833,1014,

%T 1072,1098,1297,1381,1952,1990,2421,2600,3474,3533,3602,4361,5846,

%U 6234,6926,7562,8238,10866,11240,11765,26408,26648,28258,53233,53405,67344,73453

%N Numbers k such that 273*2^k + 1 is prime.

%H Jeppe Stig Nielsen, <a href="/A053353/b053353.txt">Table of n, a(n) for n = 1..67</a> (terms n = 1..62 from Robert Price)

%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[5*10^3], PrimeQ[273*2^# + 1] &] (* _G. C. Greubel_, May 24 2018 *)

%o (PARI) is(n)=ispseudoprime(273*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%o (Magma) [n: n in [1..300] | IsPrime(273*2^n+1)];  // _G. C. Greubel_, May 24 2018

%K hard,nonn

%O 1,2

%A _N. J. A. Sloane_, Dec 29 1999

%E a(48)-a(62) from the Ray Ballinger and Wilfrid Keller link by _Robert Price_, Dec 20 2018