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A220846
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a(n) = sum_(d|n) ((product_(d|n) d) / d).
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1
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1, 3, 4, 14, 6, 72, 8, 120, 39, 180, 12, 4032, 14, 336, 360, 1984, 18, 12636, 20, 16800, 672, 792, 24, 829440, 155, 1092, 1080, 43904, 30, 1944000, 32, 64512, 1584, 1836, 1680, 25474176, 38, 2280, 2184, 5760000, 42, 7112448, 44, 162624, 157950, 3312, 48
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OFFSET
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1,2
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COMMENTS
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Conjecture: sequence is injective (all terms of this sequence occur exactly once).
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LINKS
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FORMULA
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a(p) = p + 1 for prime p.
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EXAMPLE
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The divisors of 6 are 1, 2, 3, 6. A007955(6) = product_(d|6) d = 1*2*3*6 = 36.
a(6) = 36/1 + 36/2 + 36/3 + 36/6 = 36 + 18 + 12 + 6 = 72.
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CROSSREFS
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Cf. A007955 (product of divisors of n.).
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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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