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A114374
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Number of partitions of n into parts that are not squarefree.
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6
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1, 0, 0, 0, 1, 0, 0, 0, 2, 1, 0, 0, 3, 1, 0, 0, 5, 2, 2, 0, 7, 3, 2, 0, 11, 6, 4, 3, 15, 8, 6, 3, 22, 13, 11, 6, 34, 18, 15, 9, 46, 27, 24, 17, 64, 43, 33, 23, 89, 60, 51, 37, 124, 84, 78, 51, 166, 119, 109, 78, 226, 168, 152, 118, 300, 228, 215, 166, 404, 313, 300, 230, 546, 421, 409
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OFFSET
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0,9
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COMMENTS
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LINKS
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FORMULA
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G.f.: Product_{k>=1} (1 - mu(k)^2*x^k)/(1 - x^k), where mu(k) is the Moebius function (A008683). - Ilya Gutkovskiy, Dec 30 2016
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EXAMPLE
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a(12) = #{2*2*3, 2*2*2 + 2*2, 2*2 + 2*2 + 2*2} = 3;
a(13) = #{3*3 + 2*2} = 1.
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MAPLE
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with(numtheory):
b:= proc(n, i) option remember;
`if`(n=0, 1, `if`(i<1, 0, b(n, i-1)+
`if`(i>n or issqrfree(i), 0, b(n-i, i))))
end:
a:= n-> b(n$2):
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MATHEMATICA
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b[n_, i_] := b[n, i] = If[n==0, 1, If[i<1, 0, b[n, i-1] + If[i>n || SquareFreeQ[i], 0, b[n-i, i]]]]; a[n_] := b[n, n]; Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Jun 30 2015, after Alois P. Heinz *)
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PROG
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(Haskell)
a114374 = p a013929_list where
p _ 0 = 1
p ks'@(k:ks) m = if m < k then 0 else p ks' (m - k) + p ks m
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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