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 A057099 #5 Nov 21 2019 08:15:47
%S A057099 4,8,12,12,15,16,24,24,20,21,24,40,35,30,28,36,32,48,60,36,48,45,40,
%T A057099 63,45,44,84,42,60,48,72,80,56,70,60,52,56,72,112,55,99,60,77,64,75,
%U A057099 84,96,80,68,120,63,72,144,120,96,76,105,90,72,80,143,126,120,90,84,108,91
%N A057099 Middle side of a Pythagorean triangle (ordered by the product of the sides).
%F A057099 a(n) =A057096(n)/(A057098(n)*A057100(n)) =sqrt(A057100(n)^2-A057098(n)^2)
%e A057099 a(1)=4 since 3*4*5=60 is smallest possible positive product
%t A057099 maxShortLeg = 66; terms = 67;
%t A057099 r[a_] := {a, b, c} /. {ToRules[Reduce[a <= b < c && a^2+b^2 == c^2, {b, c}, Integers]]};
%t A057099 abc = r /@ Complement[Range[maxShortLeg], {1, 2, 4}] // Flatten[#, 1]&;
%t A057099 SortBy[abc, Times @@ # &][[;; terms, 2]] (* _Jean-François Alcover_, Nov 21 2019 *)
%Y A057099 Cf. A009012, A009023, A046084, A057096.
%K A057099 nonn
%O A057099 1,1
%A A057099 _Henry Bottomley_, Aug 01 2000