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 A116021 #6 Oct 05 2019 10:52:00 %S A116021 2,4,14,27,30,65,80,113,174,332,483,498,547,684,734,737,761,944,1693, %T A116021 1855,2204,3358,3461,3647,3787,3908,4180,6144,6915,7638,7763,10249, %U A116021 10676,12235,13359,14038,16002,19736,21148,23392,23899,24295,24663 %N A116021 phi(n) plus the n-th prime gives a square. %H A116021 Harvey P. Dale, <a href="/A116021/b116021.txt">Table of n, a(n) for n = 1..500</a> %e A116021 phi(332)+p(332)=2401=49^2. %t A116021 Select[Range[25000],IntegerQ[Sqrt[EulerPhi[#]+Prime[#]]]&] (* _Harvey P. Dale_, Oct 05 2019 *) %Y A116021 Cf. A116092, A116093. %K A116021 nonn %O A116021 1,1 %A A116021 _Giovanni Resta_, Feb 13 2006