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 A331243 #5 Jan 20 2020 13:04:50
%S A331243 0,1,4,8,16,26,39,56,79,106,138,175,221,272,331,397,471,555,648,750
%N A331243 a(n) = number of triangles with integer sides i <= j <= k with diameter of enclosing circle <= n.
%C A331243 The enclosing circle differs from the circumcircle by limiting the diameter to the longest side k for obtuse triangles, i.e., those with i^2 + j^2 < k^2.
%e A331243 The sorted list of diameters D(n), rounded to 10^-4, starts: {1.1547, 2.0656, 2.3094, 3.0000, 3.0426, 3.1820, 3.4641, 4.0000, 4.0249, 4.0316, 4.1312, 4.3149, 4.6188, 5.0000, 5.0000, 5.0000, 5.0252, ...}.
%e A331243 a(1) = 0: 0 circles with D <= 1,
%e A331243 a(2) = 1: 1 circle (D = 1.1547) with 1 < D <= 2,
%e A331243 a(3) = 4: a(2) + 3 circles (D = 2.0656, 2.3094, 3.0000) with 2 < D <= 3,
%e A331243 a(4) = 8: a(3) + 4 circles (D = 3.04, 3.18, 3.46, 4.00) with 3 < D <= 4,
%e A331243 a(5) = 16: a(4) + 8 circles (D = 4.0249, ..., 5, 5, 5) with 4 < D <= 5.
%Y A331243 Cf. A331229, A331240, A331242, A331244, A331245, A331246.
%K A331243 nonn,more
%O A331243 1,3
%A A331243 _Hugo Pfoertner_, Jan 20 2020