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A351655
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Dirichlet g.f.: Product_{p prime} 1 / (1 - p^(-s) - p^(-2*s) - p^(-3*s)).
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2
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1, 1, 1, 2, 1, 1, 1, 4, 2, 1, 1, 2, 1, 1, 1, 7, 1, 2, 1, 2, 1, 1, 1, 4, 2, 1, 4, 2, 1, 1, 1, 13, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 2, 2, 1, 1, 7, 2, 2, 1, 2, 1, 4, 1, 4, 1, 1, 1, 2, 1, 1, 2, 24, 1, 1, 1, 2, 1, 1, 1, 8, 1, 1, 2, 2, 1, 1, 1, 7, 7, 1, 1, 2, 1, 1, 1
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OFFSET
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1,4
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LINKS
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FORMULA
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Multiplicative with a(p^e) = A000073(e+2).
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MATHEMATICA
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t[n_] := t[n] = t[n-1] + t[n-2] + t[n-3]; t[0] = t[1] = 0; t[2] = 1; f[p_, e_] := t[e+2]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Sep 18 2023 *)
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PROG
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(PARI) for(n=1, 87, print1(direuler(p=2, n, 1/(1 - X - X^2 - X^3))[n], ", "))
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CROSSREFS
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KEYWORD
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nonn,easy,mult
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AUTHOR
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STATUS
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approved
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