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 A083883 #11 Jan 22 2020 10:25:26
%S A083883 33,39,51,57,65,69,75,85,87,93,95,105,111,115,119,123,129,133,135,141,
%T A083883 145,147,155,159,161,165,175,177,183,185,189,195,201,203,205,207,213,
%U A083883 215,217,219,225,231,235,237,245,249,255,259,261,265,267,273,279,285
%N A083883 Odd short leg of more than one primitive Pythagorean triangle.
%H A083883 Ray Chandler, <a href="/A083883/b083883.txt">Table of n, a(n) for n = 1..10000</a>
%t A083883 Take[Transpose[Select[Tally[Transpose[Union[Sort/@({Times@@#,(Last[#]^2- First[#]^2)/2}&/@(Select[Subsets[Range[1,501,2],{2}],GCD@@#==1&]))]][[1]]], OddQ[#[[1]]]&&#[[2]]>1&]][[1]],60] (* _Harvey P. Dale_, May 28 2015 *)
%Y A083883 Cf. A081874.
%K A083883 nonn
%O A083883 1,1
%A A083883 _Lekraj Beedassy_, Jun 18 2003
%E A083883 Corrected and extended by _Ray Chandler_, Oct 29 2003