cp's OEIS Frontend

A024894 Numbers k such that 5*k + 1 is prime.

%I A024894 #30 Dec 15 2023 20:29:03
%S A024894 2,6,8,12,14,20,26,30,36,38,42,48,50,54,56,62,66,80,84,86,92,98,104,
%T A024894 108,114,120,126,128,132,138,140,150,152,162,164,176,182,188,194,198,
%U A024894 204,206,210,212,218,230,234,236,240,246,258,260,264,272,276,290,294,296,302,306,314
%N A024894 Numbers k such that 5*k + 1 is prime.
%C A024894 a(n) = (A030430(n) - 1) / 5. - _Reinhard Zumkeller_, Aug 15 2013
%H A024894 Charles R Greathouse IV, <a href="/A024894/b024894.txt">Table of n, a(n) for n = 1..10000</a>
%F A024894 a(n) ~ 0.8n log n. - _Charles R Greathouse IV_, Apr 16 2012
%t A024894 Select[Range[350], PrimeQ[5 # + 1] &] (* _Vincenzo Librandi_, May 20 2014 *)
%o A024894 (Magma) [n: n in [0..1000] | IsPrime(5*n+1)]; // _Vincenzo Librandi_, Nov 20 2010
%o A024894 (PARI) is(n)=isprime(5*n+1) \\ _Charles R Greathouse IV_, Apr 16 2012
%o A024894 (Haskell)
%o A024894 a024894 = flip div 5 . subtract 1 . a030430
%o A024894 -- _Reinhard Zumkeller_, Aug 15 2013
%Y A024894 Cf. A030430.
%K A024894 nonn,easy
%O A024894 1,1
%A A024894 _Clark Kimberling_