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A034730
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Dirichlet convolution of b_n=1 with c_n=3^(n-1).
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14
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1, 4, 10, 31, 82, 256, 730, 2218, 6571, 19768, 59050, 177430, 531442, 1595056, 4783060, 14351125, 43046722, 129146980, 387420490, 1162281262, 3486785140, 10460412256, 31381059610, 94143358444, 282429536563, 847289140888, 2541865834900, 7625599080070, 22876792454962
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OFFSET
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1,2
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LINKS
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FORMULA
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MATHEMATICA
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Rest[CoefficientList[Series[Sum[x^k/(1-3*x^k), {k, 1, 30}], {x, 0, 30}], x]] (* Vaclav Kotesovec, Sep 09 2014 *)
A034730[n_]:= DivisorSum[n, 3^(#-1) &];
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PROG
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(Magma)
A034730:= func< n | (&+[3^(d-1): d in Divisors(n)]) >;
(SageMath)
def A034730(n): return sum(3^(k-1) for k in (1..n) if (k).divides(n))
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CROSSREFS
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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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