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 A302986 #18 Sep 08 2022 08:46:21
%S A302986 0,0,1,1,1,0,2,2,2,0,1,2,2,0,3,3,4,0,2,3,3,0,4,4,5,0,4,3,4,0,4,5,5,0,
%T A302986 4,7,5,0,6,6,7,0,8,7,9,0,6,7,8,0,5,7,7,0,6,6,8,0,8,7,9,0,11,7,9,0,8,
%U A302986 10,8,0,10,13,12,0,10,11,11,0,11,11,15,0,9
%N A302986 Number of partitions of n into two distinct parts (p,q) such that p, q and |q-p| are all squarefree.
%H A302986 <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F A302986 a(n) = Sum_{i=1..floor((n-1)/2)} mu(i)^2 * mu(n-i)^2 * mu(n-2*i)^2, where mu is the Möbius function (A008683).
%F A302986 a(n) = 0 for n in A111284. - _Michel Marcus_, Apr 17 2018
%t A302986 Table[Sum[MoebiusMu[i]^2*MoebiusMu[n - i]^2*MoebiusMu[n - 2 i]^2, {i, Floor[(n - 1)/2]}], {n, 100}]
%t A302986 Table[Count[IntegerPartitions[n,{2}],_?(AllTrue[{#[[1]],#[[2]],#[[1]] - #[[2]]},SquareFreeQ]&)],{n,90}] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jan 21 2021 *)
%o A302986 (Magma) [0,0] cat [&+[(MoebiusMu(k)^2*MoebiusMu(n-k)^2)*MoebiusMu(n-2*k)^2: k in [1..Floor((n-1)/2)]]: n in [3..100]]; // _Vincenzo Librandi_, Apr 17 2018
%o A302986 (PARI) a(n) = sum(i=1, (n-1)\2, moebius(i)^2*moebius(n-i)^2*moebius(n-2*i)^2); \\ _Michel Marcus_, Apr 17 2018
%Y A302986 Cf. A008683, A111284, A294247, A303051.
%K A302986 nonn,easy
%O A302986 1,7
%A A302986 _Wesley Ivan Hurt_, Apr 16 2018