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A280320 Sum of the squares of the smaller parts of the partitions of 2n into two squarefree parts. 3
1, 5, 10, 14, 34, 66, 59, 75, 84, 220, 205, 309, 373, 600, 565, 665, 839, 1103, 959, 1191, 1176, 1860, 1416, 2060, 1664, 3653, 2194, 3505, 2891, 4974, 3563, 5534, 4371, 7551, 5845, 8874, 6742, 10409, 7061, 10145, 8037, 12414, 9030, 13327, 10849, 15319, 13473, 15960 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..48.

Index entries for sequences related to partitions

FORMULA

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

a(n) = A280316(n) - A280322(n).

MAPLE

with(numtheory): A280320:=n->add(i^2*mobius(i)^2*mobius(2*n-i)^2, i=1..n): seq(A280320(n), n=1..100);

PROG

(PARI) a(n) = sum(i=1, n, i^2*issquarefree(i)*issquarefree(2*n-i)); \\ Michel Marcus, May 16 2019

CROSSREFS

Cf. A008683, A280226, A280316, A280322.

Sequence in context: A224692 A020885 A258151 * A213365 A179123 A004470

Adjacent sequences:  A280317 A280318 A280319 * A280321 A280322 A280323

KEYWORD

nonn,easy

AUTHOR

Wesley Ivan Hurt, Dec 31 2016

STATUS

approved

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Last modified August 22 05:00 EDT 2019. Contains 326172 sequences. (Running on oeis4.)