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 A056909 #20 Aug 09 2025 07:37:58
%S A056909 7,31,127,367,631,967,1231,3727,4231,6247,7927,8287,11887,17167,21031,
%T A056909 22807,30631,34231,39607,48847,72367,108247,109567,126031,160807,
%U A056909 185767,198031,231367,235231,261127,265231,279847,290527,323767,354031,366031,373327,421207
%N A056909 Primes of the form k^2+6.
%C A056909 a(n) mod 120 = 7 or 31 for all n.
%H A056909 Vincenzo Librandi, <a href="/A056909/b056909.txt">Table of n, a(n) for n = 1..2400</a>
%F A056909 a(n) = 36*A056910(n)^2 + 12*A056910(n) + 7.
%F A056909 a(n) >> n^2 log n. - _Charles R Greathouse IV_, Nov 06 2024
%e A056909 a(2)=127 since 11^2+6=127 which is prime.
%t A056909 Intersection[Table[n^2+6,{n,0,10^2}],Prime[Range[9*10^3]]] (* or *) For[i=6,i<=6,a={};Do[If[PrimeQ[n^2+i],AppendTo[a,n^2+i]],{n,0,100}];Print["n^2+",i,",",a];i++ ] (* _Vladimir Joseph Stephan Orlovsky_, Apr 29 2008 *)
%t A056909 Select[Table[n^2+6,{n,0,7000}],PrimeQ] (* _Vincenzo Librandi_, Nov 30 2011 *)
%o A056909 (Magma) [a: n in [0..700] | IsPrime(a) where a is n^2+6]; // _Vincenzo Librandi_, Nov 30 2011
%o A056909 (PARI) list(lim)=my(v=List(),t); forstep(k=1,sqrtint(lim\1-6),2, if(isprime(t=k^2+6), listput(v,t))); Vec(v) \\ _Charles R Greathouse IV_, Nov 06 2024
%Y A056909 Cf. A002496, A056899, A049423, A005473, A056905.
%K A056909 nonn,easy
%O A056909 1,1
%A A056909 _Henry Bottomley_, Jul 07 2000