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Search: id:A125737
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| A125737 |
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Numbers that appear in the successive application of the sequence A125736 (sum of the neighbors integer-log). |
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+0
1
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OFFSET
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0,1
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COMMENT
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There are two cycles (28 38 53) and (21 22 33 29), that are the attractors in this fixed point iteration.
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EXAMPLE
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nilog(28)=ilog(27)+ilog(29)=ilog(3^3)+ilog(29)=3*3+29=38.
nilog(38)=ilog(37)+ilog(39)=ilog(37)+ilog(13*3)=37+(13+3)=53.
nilog(53)=ilog(52)+ilog(54)=ilog(2^2*13)+ilog(2*3^3)=(2*2+13)+(2+3*3)=28.
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MATHEMATICA
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iLn = Dot @@ Transpose[FactorInteger[ # ]] &; NiLn = iLn[ # - 1] + iLn[ # + 1] &; Map[Nest[NiLn, #, 19] &, Range[3, 5000]] // Union
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CROSSREFS
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Adjacent sequences: A125734 A125735 A125736 this_sequence A125738 A125739 A125740
Sequence in context: A056475 A004510 A141439 this_sequence A022391 A041890 A041892
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KEYWORD
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fini,nonn
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AUTHOR
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Carlos Alves (cjsalves(AT)gmail.com), Dec 02 2006
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