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 A236572 #10 Feb 07 2014 10:16:16
%S A236572 1,2,4,10,20,41,100,205,500,1025,2500,5125,11753,25625,58765,128125,
%T A236572 293825,640625,1469125,3203125,7345625,16015625,34867797,80078125,
%U A236572 174338985,400390625,871694925,2001953125,4358474625,10009765625,21792373125,50048828125
%N A236572 Value of y for solution of 5^n = x^2 + y^2 with closest x and y (n >= 0, 0 <= x < y).
%C A236572 Corresponding values of x: 0,1,3,5,15,38,75,190,375,950,1875,4750,10296 (A236571).
%t A236572 m = 30; Join[{1,2},Table[Reduce[{5^n== x^2+y^2,0 ≤ x ≤ y}, {x,y}, Integers][[-1,1,2]],{n,2,m}]]
%Y A236572 Cf. A121705, A236571.
%K A236572 nonn
%O A236572 0,2
%A A236572 _Zak Seidov_, Jan 29 2014