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A368582
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a(n) = floor((sigma(n) + 1) / 2).
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1
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1, 2, 2, 4, 3, 6, 4, 8, 7, 9, 6, 14, 7, 12, 12, 16, 9, 20, 10, 21, 16, 18, 12, 30, 16, 21, 20, 28, 15, 36, 16, 32, 24, 27, 24, 46, 19, 30, 28, 45, 21, 48, 22, 42, 39, 36, 24, 62, 29, 47, 36, 49, 27, 60, 36, 60, 40, 45, 30, 84, 31, 48, 52, 64, 42, 72, 34, 63
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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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a(p) = (p + 1) / 2 for all odd prime p.
a(n) = n <=> n term of union of A000079 and A000396. (If there are no odd perfect numbers also of A317306).
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MATHEMATICA
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PROG
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(Julia)
using Nemo
A368582(n::Int) = div(divisor_sigma(n, 1) + 1, 2)
println([A368582(n) for n in 1:68])
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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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