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 A030158 #11 Aug 15 2018 12:40:04
%S A030158 0,4,16,36,256,676,1296,5476,7056,9216,41616,69696,87616,147456,
%T A030158 163216,181476,329476,341056,367236,527076,541696,583696,763876,
%U A030158 781456,929296,2143296,2509056,2547216,2903616,4145296,4301476
%N A030158 Even squares in which parity of digits alternates.
%H A030158 Giovanni Resta, <a href="/A030158/b030158.txt">Table of n, a(n) for n = 1..10000</a> (First 359 terms from Vincenzo Librandi)
%F A030158 a(n) = A030157(n)^2. - _Michel Marcus_, Aug 15 2018
%t A030158 Join[{0, 4}, id[n_]:=IntegerDigits[n^2]; t={}; Do[If[Length[id[n]]==1, AppendTo[t, n], If[Union[Abs[Differences[Boole/@EvenQ[id[n]]]]]=={1}, AppendTo[t, n^2]]], {n, 4, 6000, 2}]; t] (* _Vincenzo Librandi_, Aug 15 2018 *)
%Y A030158 Cf. A030157.
%K A030158 nonn,base
%O A030158 1,2
%A A030158 _Patrick De Geest_
%E A030158 Offset changed by _Michel Marcus_, Aug 15 2018