cp's OEIS Frontend

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.

A294098 Number of partitions of 2n into two parts such that one part is squarefree and the other part is nonsquarefree.

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%I A294098 #19 Jul 27 2021 11:04:47
%S A294098 0,0,1,0,3,1,4,1,4,2,5,2,7,4,9,4,8,1,11,4,12,4,14,5,15,5,13,8,14,8,17,
%T A294098 9,19,7,18,3,19,8,23,10,25,9,26,9,22,12,25,12,27,11,27,12,28,5,31,12,
%U A294098 32,12,34,13,36,12,31,18,34,18,37,19,39,17,40,7,41
%N A294098 Number of partitions of 2n into two parts such that one part is squarefree and the other part is nonsquarefree.
%H A294098 <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F A294098 a(n) = n - Sum_{i=1..n} [c(i) = c(2*n-i)], where [] is the Iverson bracket and c is the squarefree characteristic (A008966).
%F A294098 a(n) = Sum_{i=1..n} mu(i)^2 * (1-mu(2*n-i)^2) + (1-mu(i)^2) * mu(2*n-i)^2, where mu is the Möbius function (A008683). - _Wesley Ivan Hurt_, Nov 18 2017
%t A294098 Table[n - Sum[KroneckerDelta[MoebiusMu[k]^2, MoebiusMu[2 n - k]^2], {k, n}], {n, 80}]
%t A294098 Table[Count[IntegerPartitions[2n,{2}],_?(Total[Boole[ SquareFreeQ/@#]] == 1&)],{n,80}] (* _Harvey P. Dale_, Jul 27 2021 *)
%Y A294098 Cf. A008683, A008966, A294097.
%K A294098 nonn,easy
%O A294098 1,5
%A A294098 _Wesley Ivan Hurt_, Oct 22 2017