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 A331758 #6 Feb 05 2020 13:27:39
%S A331758 4,14,40,89,186,327,562,891,1362,1957,2790,3813,5176,6795,8770,11105,
%T A331758 14020,17335,21380,25981,31306,37247,44254,52021,60956,70767,81832,
%U A331758 93971,107818,122745,139630,158011,178228,199949,223806,249349,277676,307887
%N A331758 A331757(n)/2.
%t A331758 Table[(n^2 + 4n + 1 + Sum[Sum[(2 * Boole[GCD[i, j] == 1] - Boole[GCD[i, j] == 2]) * (n + 1 - i) * (n + 1 - j), {j, 1, n}], {i, 1, n}]) / 2, {n, 1, 38}] (* _Joshua Oliver_, Feb 05 2020 *)
%Y A331758 Cf. A331757.
%K A331758 nonn
%O A331758 1,1
%A A331758 _N. J. A. Sloane_, Feb 04 2020