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

1,4

Links

Table of n, a(n) for n=1..70.

Index entries for sequences related to partitions

Formula

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

Mathematica

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

Prog

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

Crossrefs

Cf. A008683, A280226.

Sequence in context: A287863 A126088 A363833 * A085671 A126324 A035557

Adjacent sequences: A294245 A294246 A294247 * A294249 A294250 A294251

Keyword

nonn,easy

Author

Wesley Ivan Hurt, Oct 25 2017

Status

approved