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A138363
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Number of prime powers p^e with e>1 and 0<prime(n)-p^e<p.
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3
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0, 0, 1, 0, 1, 0, 1, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0
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OFFSET
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1,10
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COMMENTS
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a(31)=2, what is the next value greater than 1?.
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LINKS
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EXAMPLE
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A000040(10)=29: a(10) = #{4+5^2, 2+3^3} = 2.
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MATHEMATICA
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f[n_] := Block[{c = 0, j, k = 1, p = Prime@ n, q}, j = 1 + PrimePi@ Sqrt@ p; While[k < j, q = Prime@ k; If[p < q + q^Floor@ Log[q, p], c++ ]; k++ ]; c]; Array[f, 105]
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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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