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 A346758 #9 Aug 03 2021 15:25:46
%S A346758 0,1,2,3,6,6,12,12,18,18,30,24,42,36,48,48,72,54,90,72,96,90,132,96,
%T A346758 150,126,162,144,210,144,240,192,240,216,288,216,342,270,336,288,420,
%U A346758 288,462,360,432,396,552,384,588,450,576,504,702,486,720,576,720,630,870,576,930
%N A346758 a(n) = Sum_{d|n} mu(n/d) * floor(d^2/4).
%C A346758 Moebius transform of quarter-squares (A002620).
%F A346758 G.f.: Sum_{k>=1} mu(k) * x^(2*k) / ((1 + x^k) * (1 - x^k)^3).
%F A346758 a(n) = J_2(n) / 4 for n >= 3, where J_() is the Jordan function.
%t A346758 Table[Sum[MoebiusMu[n/d] Floor[d^2/4], {d, Divisors[n]}], {n, 1, 61}]
%t A346758 nmax = 61; CoefficientList[Series[Sum[MoebiusMu[k] x^(2 k)/((1 + x^k) (1 - x^k)^3), {k, 1, nmax}], {x, 0, nmax}], x] // Rest
%o A346758 (PARI) a(n) = sumdiv(n, d, moebius(n/d)*(d^2\4)); \\ _Michel Marcus_, Aug 03 2021
%Y A346758 Cf. A002620, A007434, A023022, A346759.
%K A346758 nonn
%O A346758 1,3
%A A346758 _Ilya Gutkovskiy_, Aug 02 2021