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 A114335 #24 Mar 17 2025 11:41:03
%S A114335 4,10,14,20,26,40,110,124,146,206,250,326,340,350,436,440,470,634,686,
%T A114335 704,920,1004,1054,1060,1124,1156,1246,1276,1294,1316,1376,1420,1550,
%U A114335 1570,1654,1664,1784,1966,1970,2026,2116,2210,2380,2516,2594,2654,2780
%N A114335 Numbers k such that k^2 + 1 and k^2 - 3 are both prime.
%C A114335 This is the intersection of A028873 and A005574; this sequence is also a subset of A090120 (n such that closest primes above and below n^2 differ by 4).
%H A114335 Amiram Eldar, <a href="/A114335/b114335.txt">Table of n, a(n) for n = 1..10000</a>
%e A114335 a(2) = 10 since 10^2 + 1 = 101 and 10^2 - 3 = 97 are both prime.
%t A114335 Select[Range[3,3000],AllTrue[#^2+{1,-3},PrimeQ]&] (* _Harvey P. Dale_, Jul 25 2024 *)
%o A114335 (Magma) [n: n in [2..100000] |IsPrime(n^2+1) and IsPrime(n^2-3)]; // _Vincenzo Librandi_, Nov 13 2010
%o A114335 (PARI) isok(k) = isprime(k^2 + 1) && isprime(k^2 - 3); \\ _Amiram Eldar_, Mar 01 2025
%Y A114335 Cf. A005574, A028873, A090120.
%K A114335 nonn
%O A114335 1,1
%A A114335 _John L. Drost_, Feb 07 2006