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 A280169 #5 Feb 16 2025 08:33:38
%S A280169 1,0,0,1,0,1,1,1,1,1,2,2,2,3,3,4,4,5,6,6,8,9,10,11,13,14,17,18,21,24,
%T A280169 26,30,33,38,42,47,53,58,65,73,80,90,99,110,122,134,149,164,181,199,
%U A280169 220,242,266,292,321,352,386,424,463,507,554,606,662,722,788,860,936,1020,1111,1208,1314,1428,1553,1685,1829,1984,2152
%N A280169 Expansion of Product_{k>=2} 1/(1 - mu(2*k-1)^2*x^(2*k-1)), where mu() is the Moebius function (A008683).
%C A280169 Number of partitions of n into odd squarefree parts > 1.
%H A280169 Joerg Arndt, <a href="http://www.jjj.de/fxt/#fxtbook">Matters Computational (The Fxtbook)</a>, section 16.4.3 "Partitions into square-free parts", pp.351-352
%H A280169 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Squarefree.html">Squarefree</a>
%H A280169 <a href="/index/Par#partN">Index entries for related partition-counting sequences</a>
%F A280169 G.f.: Product_{k>=2} 1/(1 - mu(2*k-1)^2*x^(2*k-1)).
%e A280169 a(13) = 3 because we have [13], [7, 3, 3] and [5, 5, 3].
%t A280169 nmax = 76; CoefficientList[Series[Product[1/(1 - MoebiusMu[2 k - 1]^2 x^(2 k - 1)), {k, 2, nmax}], {x, 0, nmax}], x]
%Y A280169 Cf. A005117, A008683, A056911, A073576, A134345, A144338, A280127.
%K A280169 nonn
%O A280169 0,11
%A A280169 _Ilya Gutkovskiy_, Dec 27 2016