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Search: id:A113286
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| A113286 |
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Let S(n)=1/4*Sigma(n) . Numbers such that S(S(n))=n, 1/4-Sociable number of order 1 or 2. |
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1
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OFFSET
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1,1
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COMMENT
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a(1) and a(2) are 4 multiple perfect numbers. a(4)=S(a(3)). I calculated {2096640,2234232}. It is unknown if any pair exists between {a(3),a(4)} and this pair.
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LINKS
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Eric Weisstein's World of Mathematics, WathWorld
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CROSSREFS
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Cf. A113546.
Sequence in context: A066576 A104877 A027665 this_sequence A027687 A109485 A156429
Adjacent sequences: A113283 A113284 A113285 this_sequence A113287 A113288 A113289
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KEYWORD
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nonn
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AUTHOR
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Yasutoshi Kohmoto zbi74583(AT)boat.zero.ad.jp, Jan 27 2006
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