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A341067
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Number of ways to write n as an ordered sum of 7 squarefree numbers.
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8
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1, 7, 28, 77, 168, 315, 553, 932, 1505, 2282, 3297, 4634, 6447, 8771, 11607, 15029, 19390, 24885, 31500, 39137, 48335, 59584, 73003, 88109, 105525, 126112, 150472, 177632, 208160, 243194, 284102, 329357, 379379, 435477, 500108, 571124, 648998, 735112, 833483, 940765, 1057679
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OFFSET
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7,2
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LINKS
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FORMULA
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G.f.: (Sum_{k>=1} mu(k)^2 * x^k)^7.
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MAPLE
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b:= proc(n, t) option remember;
`if`(n=0, `if`(t=0, 1, 0), `if`(t<1, 0, add(
`if`(numtheory[issqrfree](j), b(n-j, t-1), 0), j=1..n)))
end:
a:= n-> b(n, 7):
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MATHEMATICA
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nmax = 47; CoefficientList[Series[Sum[MoebiusMu[k]^2 x^k, {k, 1, nmax}]^7, {x, 0, nmax}], x] // Drop[#, 7] &
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CROSSREFS
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Cf. A005117, A008683, A008966, A098235, A280210, A308952, A341064, A341065, A341066, A341068, A341069, A341070.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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