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 A114069 #12 Aug 13 2019 11:22:32 %S A114069 33,90,385,420,649,900,1441,1464,1480,1729,2025,2616,3168,3588,3984, %T A114069 4005,4873,5049,5185,6225,7153,7585,8740,9060,10285,11080,12280,12609, %U A114069 13914,14809,15136,16065,16345,17017,17353,17809,18073,18625,19098 %N A114069 sigma(n) + n is a square. %H A114069 Amiram Eldar, <a href="/A114069/b114069.txt">Table of n, a(n) for n = 1..10000</a> %e A114069 sigma(33) + 33 = 81 = 9^2. %t A114069 Select[Range[20000],IntegerQ[Sqrt[DivisorSigma[1,#]+#]]&] (* _Harvey P. Dale_, May 09 2011 *) %o A114069 (PARI) isok(n) = issquare (n+sigma(n)); \\ _Michel Marcus_, Aug 13 2019 %Y A114069 Cf. A000203, A155085. %K A114069 nonn %O A114069 1,1 %A A114069 _Giovanni Resta_, Feb 13 2006