A294248 Number of partitions of 2n into two distinct squarefree parts.

0, 1, 1, 3, 1, 3, 2, 5, 4, 5, 4, 7, 4, 6, 4, 8, 6, 11, 6, 11, 7, 12, 7, 13, 8, 13, 10, 13, 10, 14, 10, 15, 10, 17, 12, 21, 13, 19, 12, 20, 12, 21, 13, 23, 17, 22, 16, 24, 17, 25, 17, 26, 18, 31, 18, 29, 19, 30, 19, 31, 19, 32, 23, 30, 22, 31, 22, 32, 22, 34

Offset: 1

Author

Wesley Ivan Hurt, Oct 25 2017

Keywords

• nonn
• easy

Links

• Index entries for sequences related to partitions

Crossrefs

Cf. A008683, A280226.

Programs

Mathematica

Table[Sum[MoebiusMu[i]^2*MoebiusMu[2 n - i]^2, {i, n - 1}], {n, 80}]

PARI

A294248(n)=sum(i=1,n-1,moebius(i)^2*moebius(2*n-i)^2); \\ R. J. Cano, Oct 25 2017

Formula

a(n) = Sum_{i=1..n-1} mu(i)^2 * mu(2n-i)^2, where mu is the Möbius function (A008683).