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 A062784 #19 Jun 29 2018 02:16:48 %S A062784 2,4,56,110,125,161,287,391,418,423,511,588,609,675,721,799,910,935, %T A062784 1048,1057,1102,1130,1281,1351,1457,1485,1630,1716,1799,1826,1921, %U A062784 2047,2060,2177,2255,2378,2403,2449,2457,2472,3199,3266,3915,4010,4376,4417 %N A062784 Numbers k such that sigma(k) + phi(k) is a perfect square. %H A062784 Harry J. Smith, <a href="/A062784/b062784.txt">Table of n, a(n) for n = 1..1000</a> %t A062784 Select[Range[4500],IntegerQ[Sqrt[DivisorSigma[1,#]+EulerPhi[#]]]&] (* _Harvey P. Dale_, Jan 18 2012 *) %o A062784 (PARI) select(k->issquare(sigma(k) + eulerphi(k)), [1..5000]) %Y A062784 Cf. A065387. %K A062784 nonn %O A062784 1,1 %A A062784 _Jason Earls_, Jul 18 2001