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 A089593 #21 Sep 08 2022 08:45:12 %S A089593 0,1,3,5,9,13,15,19,23,25,35,39,53,55,65,73,83,89,93,109,115,119,123, %T A089593 125,129,133,145,149,155,159,169,175,179,183,203,205,209,223,229,235, %U A089593 239,249,255,259,263,269,279,283,299,305,313,325,339,349 %N A089593 Numbers k such that k^2 + 2k + 2 is prime. %D A089593 M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988 %D A089593 Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta, UTET, CittaStudiEdizioni, Milano 1997 %H A089593 Vincenzo Librandi, <a href="/A089593/b089593.txt">Table of n, a(n) for n = 1..1000</a> %F A089593 a(n) = A005574(n)-1 = A090693(n)-2. %t A089593 Select[Range[0,1000],PrimeQ[#^2+2#+2]&] (* _Vincenzo Librandi_, May 23 2014 *) %o A089593 (Magma)[n: n in [0..400]|IsPrime(n^2+2*n+2)]; // _Vincenzo Librandi_, Dec 17 2010 %o A089593 (PARI) is(n)=isprime(n^2+2*n+2) \\ _Charles R Greathouse IV_, Jun 12 2017 %Y A089593 Cf. A002496 gives the primes, A005574, A090693. %K A089593 nonn,easy %O A089593 1,3 %A A089593 _Giovanni Teofilatto_, Dec 30 2003 %E A089593 Corrected by _Vincenzo Librandi_, Dec 17 2010