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A066238
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The floor(n/3)-perfect numbers, where f-perfect numbers for an arithmetical function f are defined in A066218.
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0
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2, 12, 18, 40, 56, 304, 550, 748, 1504, 3230, 3770, 6976, 29824, 124672, 351351, 382772, 510464, 537248, 698528, 791264, 1081568, 1279136, 2065408, 2279072, 211855016, 561841408, 731378944, 3365232128, 3557004544
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OFFSET
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1,1
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COMMENTS
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It appears that there are more floor(n/N)-perfect numbers the larger N is. (Here N = 3.)
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LINKS
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EXAMPLE
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Let f(n) = floor(n/3). Then f(12) = 6 = 3+2+1+0 = f(6)+f(4)+f(3)+f(1); so 12 is a term of the sequence.
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MATHEMATICA
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f[x_] := Floor[x/3]; Select[ Range[2, 10^5], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ]
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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