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 A171140 #11 Jan 23 2022 20:04:07 %S A171140 3,7,19,27,47,59,87,139,159,227,279,307,367,467,579,619,747,839,887, %T A171140 1039,1147,1319,1567,1699,1767,1907,1979,2127,2687,2859,3127,3219, %U A171140 3699,3799,4107,4427,4647,4987,5339,5459,6079,6207,6467,6599,7419,8287,8587 %N A171140 Numbers k such that 6*k + 7 = p^2 (p=prime). %C A171140 Subsequence of A164097. - _R. J. Mathar_, Jul 06 2010 %H A171140 Vincenzo Librandi, <a href="/A171140/b171140.txt">Table of n, a(n) for n = 1..1000</a> %e A171140 6*3 + 7 = 5^2, so 3 is a term; %e A171140 6*7 + 7 = 7^2, so 7 is a term; %e A171140 6*19 + 7 = 11^2, so 19 is a term; %e A171140 6*27 + 7 = 13^2, so 27 is a term. %t A171140 Select[Range[10000], PrimeQ[Sqrt[6 # + 7]]&] (* _Vincenzo Librandi_, Apr 06 2013 *) %o A171140 (Magma) [(p^2-7)/6: p in PrimesInInterval(4, 250)]; // _Vincenzo Librandi_, Apr 06 2013 %Y A171140 Cf. A164097. %K A171140 nonn,easy %O A171140 1,1 %A A171140 _Vincenzo Librandi_, Dec 04 2009