This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A089373 #27 Jan 23 2025 16:52:46 %S A089373 0,7,10,12,15,16,22,25,27,31,36,37,40,46,51,52,55,57,60,61,67,75,85, %T A089373 87,90,97,102,106,111,120,136,151,156,157,162,171,172,177,180,186,192, %U A089373 202,205,211,220,222,225,237,240,241,250,255,261,267,271,277,282,286,291,292 %N A089373 Numbers k such that k^2 - 7*k + 7 is prime. %D A089373 M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna, 1988. %D A089373 Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta, UTET, CittaStudiEdizioni, Milano, 1997. %H A089373 Vincenzo Librandi, <a href="/A089373/b089373.txt">Table of n, a(n) for n = 1..10000</a> %t A089373 Column[(0),Select[Range[6,200],PrimeQ[ #^2-7#+7]&]] (* _Vincenzo Librandi_, Dec 12 2011 *) %o A089373 (Magma) [0] cat [n: n in [6..300] | IsPrime(n^2 - 7*n + 7)]; // _Vincenzo Librandi_, Dec 12 2011 %o A089373 (PARI) is(n)=isprime(n^2-7*n+7) \\ _Charles R Greathouse IV_, May 22 2017 %o A089373 (GAP) Concatenation([0],Filtered([7..300],k->IsPrime(k^2-7*k+7))); # _Muniru A Asiru_, Nov 24 2018 %Y A089373 Cf. A089376 (primes of the form k^2 - 7*k + 7). %K A089373 easy,nonn %O A089373 1,2 %A A089373 _Giovanni Teofilatto_, Dec 27 2003 %E A089373 More terms from _David Wasserman_, Sep 15 2005 %E A089373 a(1)=0 inserted by _Vincenzo Librandi_, Dec 12 2011