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 A006339 #31 Feb 16 2025 08:32:30
%S A006339 1,5,25,125,65,3125,15625,325,390625,1953125,1625,48828125,4225,1105,
%T A006339 6103515625,30517578125,40625,21125,3814697265625,203125,
%U A006339 95367431640625,476837158203125,5525,11920928955078125,274625,5078125,1490116119384765625,528125,25390625,186264514923095703125
%N A006339 Least hypotenuse of n distinct Pythagorean triangles.
%H A006339 Ray Chandler, <a href="/A006339/b006339.txt">Table of n, a(n) for n = 0..1438</a> (a(1439) exceeds 1000 digits).
%H A006339 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CircleLatticePoints.html">Circle Lattice Points</a>
%H A006339 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PythagoreanTriple.html">Pythagorean Triple</a>
%t A006339 oneModFourPrimes[1] = 5;
%t A006339 oneModFourPrimes[n_] := oneModFourPrimes[n] = NestWhile[NextPrime, NextPrime[oneModFourPrimes[n - 1]], Mod[#, 4] != 1 & ];
%t A006339 factorizations[1, limit_] = {{}};
%t A006339 factorizations[n_, limit_] := factorizations[n, limit] = Join @@ Table[Prepend[#, d]& /@ factorizations[n/d, d], {d, Select[Rest[Divisors[n]], # <= limit & ]}];
%t A006339 leastHypotenuse[n_] := Min[(Times @@ (Array[oneModFourPrimes, Length[#]]^((# - 1)/2)) & ) /@ factorizations[2*n + 1, 2*n + 1]];
%t A006339 Array[leastHypotenuse, 30, 0]
%t A006339 (* Albert H. Mao, Jan 06 2012 *)
%Y A006339 Except for offset, same as A046112.
%K A006339 nonn
%O A006339 0,2
%A A006339 _David W. Wilson_