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 A308133 #8 Jun 18 2020 13:40:45
%S A308133 0,0,1,0,1,2,3,2,3,0,4,2,6,5,14,10,13,11,11,6,13,13,23,18,15,11,29,20,
%T A308133 29,39,55,46,54,44,72,57,70,54,100,75,91,64,111,82,139,102,171,135,
%U A308133 172,123,171,114,176,145,176,140,163,128,199,152,204,207,283
%N A308133 Sum of the smallest sides of all integer-sided triangles with squarefree sides and perimeter n.
%H A308133 Wikipedia, <a href="https://en.wikipedia.org/wiki/Integer_triangle">Integer Triangle</a>
%F A308133 a(n) = Sum_{k=1..floor(n/3)} Sum_{i=k..floor((n-k)/2)} sign(floor((i+k)/(n-i-k+1))) * mu(i)^2 * mu(k)^2 * mu(n-i-k)^2 * k, where mu is the Möbius function (A008683).
%t A308133 Table[Sum[Sum[k*MoebiusMu[i]^2*MoebiusMu[k]^2*MoebiusMu[n - k - i]^2*Sign[Floor[(i + k)/(n - i - k + 1)]], {i, k, Floor[(n - k)/2]}], {k, Floor[n/3]}], {n, 100}]
%Y A308133 Cf. A008683, A308116.
%K A308133 nonn
%O A308133 1,6
%A A308133 _Wesley Ivan Hurt_, May 14 2019