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A076048
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Number of prime powers p^k (k != 1) <= 10^n.
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4
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1, 4, 11, 26, 52, 109, 237, 556, 1405, 3690, 10085, 28157, 80071, 230568, 670122, 1962690, 5782468, 17124206, 50930440, 152043592, 455389240, 1367883344, 4119448337, 12434731102, 37613760490, 113995567275, 346090346047, 1052421430209
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OFFSET
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0,2
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LINKS
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EXAMPLE
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a(2)=11 because 1, 4, 8, 9, 16, 25, 27, 32, 49, 64 & 81 are the only prime powers less than 100.
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MATHEMATICA
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f[n_] := Block[{t = 1, k = 2}, While[s = PrimePi[10^(n/k)]; s != 0, t = t + s; k++ ]; t]; Table[ f[n], {n, 0, 27}]
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PROG
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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