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Primes of the form k^2 - 7*k + 7.
3

%I #18 Sep 08 2022 08:45:12

%S 7,37,67,127,151,337,457,547,751,1051,1117,1327,1801,2251,2347,2647,

%T 2857,3187,3301,4027,5107,6637,6967,7477,8737,9697,10501,11551,13567,

%U 17551,21751,23251,23557,25117,28051,28387,30097,31147,33301,35527

%N Primes of the form k^2 - 7*k + 7.

%D M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna, 1988.

%D Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta, UTET, CittaStudiEdizioni, Milano, 1997.

%H Vincenzo Librandi, <a href="/A089376/b089376.txt">Table of n, a(n) for n = 1..5000</a>

%F a(n) = A089373(n)^2 - 7*A089373(n) + 7. - _David Wasserman_, Sep 15 2005

%p select(isprime,[k^2-7*k+7$k=1..250]); # _Muniru A Asiru_, Nov 24 2018

%t Select[Table[n^2-7n+7,{n,6,1000}],PrimeQ] (* _Vincenzo Librandi_, Dec 12 2011 *)

%o (Magma) [a: n in [6..200] | IsPrime(a) where a is n^2 - 7*n + 7]; // _Vincenzo Librandi_, Dec 12 2011

%Y Cf. A089373 (corresponding k).

%K nonn,easy

%O 1,1

%A _Giovanni Teofilatto_, Dec 27 2003

%E More terms from _David Wasserman_, Sep 15 2005