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Search: id:A066238
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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
1
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| 2, 12, 18, 40, 56, 304, 550, 748, 1504, 3230, 3770, 6976, 29824
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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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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J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (2002-2003), 168-172.
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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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Sequence in context: A063576 A120350 A032413 this_sequence A101074 A115109 A048001
Adjacent sequences: A066235 A066236 A066237 this_sequence A066239 A066240 A066241
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KEYWORD
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nonn
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AUTHOR
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Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 19 2001
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