A185658 - OEIS

%I #21 Jul 10 2017 02:22:18

%S 41,47,167,179,379,397,677,701,1061,1091,1531,1567,2087,2129,2729,

%T 2777,3457,3511,4271,5171,5237,6229,7229,7307,8387,9631,9721,11057,

%U 12377,12479,13879,15467,15581,20747,20879,22679,22817

%N Primes of the form 43*n^2 + 3*n + 1.

%C Also primes of the form (n^2 + n + 41) / 43. Note that in the form 43n^2 + 3n + 1, both positive and negative n must be considered.

%H G. C. Greubel, <a href="/A185658/b185658.txt">Table of n, a(n) for n = 1..10000</a>

%t a={}; Do[p=(n^2+n+41)/43; If[PrimeQ[p], AppendTo[a, p]], {n, 10^4}]; Print[a];

%o (PARI) for(n=1,1e2,if(isprime(t=43*n^2-3*n+1), print1(t", ")); if(isprime(t=43*n^2+3*n+1), print1(t", "))) \\ _Charles R Greathouse IV_, Feb 27 2011

%Y Cf. A185657.

%K nonn,easy

%O 1,1

%A _Michel Lagneau_, Feb 08 2011