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 A081759 #27 Feb 04 2024 01:15:09 %S A081759 1,5,7,11,13,19,25,29,35,37,41,47,49,53,55,61,65,79,83,85,91,97,103, %T A081759 107,113,119,125,127,131,137,139,149,151,161,163,175,181,187,193,197, %U A081759 203,205,209,211,217,229,233,235,239,245,257,259,263,271,275,289 %N A081759 Numbers n such that 5n+6 is prime. %D A081759 M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988 %D A081759 Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta, UTET, CittaStudiEdizioni, Milano 1997 %H A081759 Nathaniel Johnston, <a href="/A081759/b081759.txt">Table of n, a(n) for n = 1..10000</a> %F A081759 a(n) = 2*A024912(n) - 1. %p A081759 A081759 := proc(n) option remember: local k: if(n=1)then return 1: fi: for k from procname(n-1)+1 do if(isprime(5*k+6))then return k: fi: od: end: seq(A081759(n),n=1..100); # _Nathaniel Johnston_, May 28 2011 %t A081759 Select[Range[300], PrimeQ[5# + 6] &] (* _Ray Chandler_, Dec 06 2006 *) %o A081759 (Magma) [n: n in [0..300]| IsPrime(5*n + 6)]; // _Vincenzo Librandi_, Oct 16 2012 %o A081759 (PARI) is(n)=isprime(5*n+6) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A081759 Cf. A024912, A030430, A049511, A067076, A087505, A089192, A089253. %K A081759 easy,nonn %O A081759 1,2 %A A081759 _Giovanni Teofilatto_, Nov 21 2003 %E A081759 Corrected by _Ray Chandler_, Nov 22 2003