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Primes of the form 2*n^2+86*n+41.
2

%I #7 Sep 08 2022 08:46:08

%S 317,521,857,977,1229,1361,1637,2081,2237,2729,3257,3821,4217,4421,

%T 5501,6197,8501,9341,9629,12401,13397,14081,15137,15497,16229,18521,

%U 18917,20129,21377,22229,23537,23981,26261,26729,29129,31121,32141,35837,36929,39161

%N Primes of the form 2*n^2+86*n+41.

%C Subsequence of A040117.

%C Conjecture: except 521, 2^a(n)-1 is not prime; in other words, these primes are included in A054723.

%H Vincenzo Librandi, <a href="/A243958/b243958.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Table[2 n^2 + 86 n + 41, {n, 800}], PrimeQ]

%o (Magma) [a: n in [1..300] | IsPrime(a) where a is 2*n^2+86*n+41];

%Y Cf. A040117.

%Y Cf. similar sequences listed in A243888.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Jun 16 2014