cp's OEIS Frontend

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.

A260557 Primes p such that p = q^2 + 10*r^2 where q and r are also primes.

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%I A260557 #12 Oct 08 2024 14:53:41
%S A260557 89,139,211,379,401,419,499,569,619,659,881,1019,1051,1091,1259,1409,
%T A260557 1451,1459,1499,1571,1619,1699,1721,1811,1889,1931,1979,2099,2339,
%U A260557 2459,2531,2579,2699,2939,3011,3251,3299,3371,3539,3571,3659,3761,3779,3851,4019
%N A260557 Primes p such that p = q^2 + 10*r^2 where q and r are also primes.
%C A260557 Green & Sawhney prove that this sequence is infinite. - _Charles R Greathouse IV_, Oct 08 2024
%H A260557 Colin Barker, <a href="/A260557/b260557.txt">Table of n, a(n) for n = 1..1750</a>
%H A260557 Ben Green and Mehtaab Sawhney, <a href="https://arxiv.org/abs/2410.04189">Primes of the form p^2 + nq^2</a>, arXiv preprint (2024). arXiv:2410.04189 [math.NT]
%e A260557 419 is in the sequence because 419 = 13^2 + 10*5^2 and 419, 13 and 5 are all primes.
%t A260557 Select[#1^2 + 10 #2^2 & @@ # & /@ Tuples[Prime@ Range@ 36, 2], PrimeQ] // Sort (* _Michael De Vlieger_, Jul 29 2015 *)
%o A260557 (PARI) list(lim)=my(v=List()); lim\=1; forprime(q=2, sqrtint((lim-9)\10), my(t=10*q^2); forprime(p=3, sqrtint(lim-t), my(r=t+p^2); if(isprime(r), listput(v, r)))); Set(v) \\ _Charles R Greathouse IV_, Oct 08 2024
%Y A260557 Cf. A260553, A260554, A260555, A260556.
%K A260557 nonn
%O A260557 1,1
%A A260557 _Colin Barker_, Jul 29 2015