|
%I #22 Sep 08 2022 08:45:52
%S 2,9,11,12,14,17,21,24,26,39,44,47,59,77,86,87,89,101,116,117,122,126,
%T 131,137,147,152,161,164,177,179,189,191,192,201,212,219,222,231,249,
%U 257,261,264,284,287,296,306,317,326,329,336,347,369,387,389,411,417
%N Numbers n>0 such that 2*n^2+14*n+5 is prime.
%C Conjecture: If p = 2*n^2 + 14*n + 5 then 2^p - 1 is not prime.
%H Vincenzo Librandi, <a href="/A176545/b176545.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Range[500], PrimeQ[2#^2 + 14# + 5] &] (* _Harvey P. Dale_, Jan 09 2011 *)
%o (Magma) [n: n in [1..1000]| IsPrime(2*n^2+14*n+5)]
%Y Cf. A154577 (Primes of the form 2n^2 + 14n + 5), A144562(Triangle read by rows where T(m, n) = 2m*n + m + n - 1).
%K nonn,easy
%O 1,1
%A _Vincenzo Librandi_, Apr 20 2010
|
