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URL: https://oeis.org/A294239

⇱ A294239 - OEIS


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A294239
Sum of the parts in the partitions of n into two parts with larger part nonsquarefree.
2
0, 0, 0, 0, 5, 6, 7, 8, 9, 20, 22, 24, 39, 42, 45, 48, 51, 54, 57, 60, 84, 88, 92, 96, 100, 130, 135, 168, 203, 210, 217, 224, 231, 238, 245, 252, 259, 266, 273, 280, 287, 294, 301, 308, 360, 414, 423, 432, 441, 500, 510, 520, 583, 594, 605, 616, 627, 638
OFFSET
1,5
FORMULA
a(n) = n * Sum_{i=1..floor(n/2)} (1 - mu(n-i)^2), where mu is the Möbius function (A008683).
MATHEMATICA
Table[n*Sum[(1 - MoebiusMu[n - k]^2), {k, Floor[n/2]}], {n, 80}]
PROG
(PARI) a(n) = n*sum(i=1, n\2, 1-moebius(n-i)^2); \\ Michel Marcus, Feb 11 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Oct 25 2017
STATUS
approved