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A364933
a(n) = Sum_{k=1..n} A191898(n,k)*[A191904(n,k) = A191898(n,k)].
0
0, -1, -1, 0, -1, -2, -1, 2, 3, -2, -1, 0, -1, -2, 1, 6, -1, 2, -1, 2, 3, -2, -1, 4, 15, -2, 15, 4, -1, 0, -1, 14, 7, -2, 13, 8, -1, -2, 9, 10, -1, 2, -1, 8, 17, -2, -1, 12, 35, 14, 13, 10, -1, 14, 25, 16, 15, -2, -1, 8, -1, -2, 27, 30, 31, 6, -1, 14, 19, 12
OFFSET
1,6
FORMULA
a(n) = Sum_{k=1..n} A191898(n,k)*[A191904(n,k) = A191898(n,k)].
Conjecture: a(n) = A057859(n) - A008472(n) - 1.
MATHEMATICA
f[n_] := DivisorSum[n, MoebiusMu[#] # &]; Table[Sum[If[If[Mod[n, k] == 0, 1 - k, 1] == f[GCD[n, k]], f[GCD[n, k]], 0], {k, 1, n}], {n, 1, 70}]
CROSSREFS
KEYWORD
sign
AUTHOR
Mats Granvik, Aug 13 2023
STATUS
approved