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 A109807 #7 Dec 15 2017 17:36:55 %S A109807 1,2,4,6,10,14,16,20,24,26,36,40,56,66,74,94,116,120,130,134,146,160, %T A109807 170,176,204,230,250,256,260,284,314,326,340,350,386,406,430,440,444, %U A109807 464,466,470,490,496,536,556,570,584,634,646,654,680,686,700,704,714 %N A109807 Numbers n such that n^2 + 1 is a Chen prime. %H A109807 Harvey P. Dale, <a href="/A109807/b109807.txt">Table of n, a(n) for n = 1..1000</a> %t A109807 Select[Range[800],PrimeQ[#^2+1]&&PrimeOmega[#^2+3]<3&] (* _Harvey P. Dale_, May 07 2015 *) %o A109807 (PARI) is(n)=isprime(n^2+1) && bigomega(n^2+3)<3 \\ _Charles R Greathouse IV_, Aug 19 2015 %Y A109807 Subsequence of A005574. %Y A109807 Cf. A005574, A109611. %K A109807 nonn %O A109807 1,2 %A A109807 _Jason Earls_, Aug 16 2005