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A372470
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Multiplicative with a(p^e) = e+1 if e+1 is a power of 2, and 0 otherwise.
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3
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1, 2, 2, 0, 2, 4, 2, 4, 0, 4, 2, 0, 2, 4, 4, 0, 2, 0, 2, 0, 4, 4, 2, 8, 0, 4, 4, 0, 2, 8, 2, 0, 4, 4, 4, 0, 2, 4, 4, 8, 2, 8, 2, 0, 0, 4, 2, 0, 0, 0, 4, 0, 2, 8, 4, 8, 4, 4, 2, 0, 2, 4, 0, 0, 4, 8, 2, 0, 4, 8, 2, 0, 2, 4, 0, 0, 4, 8, 2, 0, 0, 4, 2, 0, 4, 4, 4
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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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f[p_, e_] := If[e + 1 == 2^IntegerExponent[e + 1, 2], e + 1, 0]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100]
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PROG
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(PARI) a(n) = vecprod(apply(x -> if(x+1 == 1 << valuation(x+1, 2), x+1, 0), factor(n)[, 2]));
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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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