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A351834
Number of partitions of n into exactly two distinct parts, at least one of which is squarefree.
1
0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 4, 5, 6, 7, 6, 7, 8, 9, 7, 9, 9, 11, 9, 11, 11, 12, 10, 12, 13, 14, 12, 14, 14, 16, 12, 16, 17, 18, 15, 18, 19, 19, 16, 19, 21, 22, 18, 21, 23, 24, 18, 22, 23, 26, 21, 24, 24, 27, 22, 26, 27, 28, 24, 28, 29, 30, 24, 30, 30, 33, 24, 32, 32, 34, 27
OFFSET
1,5
FORMULA
a(n) = Sum_{k=1..floor((n-1)/2)} (mu(k)^2 + mu(n-k)^2 - mu(k)^2*mu(n-k)^2), where mu is the Möbius function.
CROSSREFS
Cf. A005117, A008683 (mu), A351833.
Sequence in context: A167232 A319468 A137791 * A096125 A140828 A262907
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Feb 21 2022
STATUS
approved