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Numbers k such that 10*k - 97 is prime.
2

%I #21 Oct 23 2023 01:37:14

%S 10,11,12,14,15,17,18,20,21,26,27,29,32,33,36,38,39,41,45,47,48,53,54,

%T 56,60,62,66,69,71,74,75,77,78,83,84,87,92,95,96,98,105,108,111,113,

%U 116,119,120,122,125,126,129,131,132,138,140

%N Numbers k such that 10*k - 97 is prime.

%H Michael De Vlieger, <a href="/A108584/b108584.txt">Table of n, a(n) for n = 1..10000</a>

%e If k=10 then 10*k - 97 = 3 (prime).

%e If k=36 then 10*k - 97 = 263 (prime).

%t Select[Range[10,200],PrimeQ[10#-97]&] (* _Harvey P. Dale_, Jan 10 2015 *)

%o (Magma) [n: n in [10..200]| IsPrime(10*n - 97)]; // _Vincenzo Librandi_, Feb 03 2011

%o (PARI) is(n)=isprime(10*n-97) \\ _Charles R Greathouse IV_, Jun 13 2017

%o (SageMath) [n for n in (10..400) if is_prime(10*n-97)] # _G. C. Greubel_, Oct 22 2023

%Y Cf. A108588.

%K nonn,easy

%O 1,1

%A _Parthasarathy Nambi_, Jul 05 2005