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 A027754 #23 Sep 08 2022 08:44:49 %S A027754 0,1,2,3,6,7,11,16,17,18,21,23,27,31,32,38,42,48,51,62,67,72,73,76,77, %T A027754 83,86,91,93,97,108,111,116,121,126,133,136,137,146,153,158,163,172, %U A027754 177,182,188,191,192,193,202,212,213,216,223,226,231,247,248 %N A027754 Numbers k such that k^2 + k + 5 is prime. %H A027754 Seiichi Manyama, <a href="/A027754/b027754.txt">Table of n, a(n) for n = 1..10000</a> %H A027754 Patrick De Geest, <a href="http://www.worldofnumbers.com/index.html">World!Of Numbers</a> %e A027754 Since 3^2 + 3 + 5 = 17, which is prime, 3 is in the sequence. %e A027754 Since 4^2 + 4 + 5 = 25 = 5^2, 4 is not in the sequence. %t A027754 Select[Range[0, 499], PrimeQ[#^2 + # + 5] &] (* _Alonso del Arte_, Nov 28 2016 *) %o A027754 (Magma) [n: n in [0..1000] |IsPrime(n^2+n+5)] // _Vincenzo Librandi_, Nov 20 2010 %Y A027754 Cf. A014556, A027755. %K A027754 nonn %O A027754 1,3 %A A027754 _Patrick De Geest_