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Search: id:A054982
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| A054982 |
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a(n)=Min[ x ], the least composite number such that Sigma[ a(n)+n! ]=n!+Sigma[ a(n) ] where Sigma()=A000203. |
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+0
4
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| 434, 104, 80, 182, 427, 1727, 4147, 7163, 42031, 165841, 569257, 2683909
(list; graph; listen)
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OFFSET
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2,1
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EXAMPLE
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a(7)=1727=11*157, 4 divisors, 5040+Sigma[1727]=1896+5040=6936, Sigma[1727+5040]=Sigma[6767]=1+67+101+6767=6936; a(2)=A054799(24)=434,a(3)=A015914(19)=104, the first composites in that series
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MATHEMATICA
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L = {}; Do[i = 1; While[ ! ((Plus @@ Divisors[i + j! ] == j! + Plus @@ Divisors[i]) && ! PrimeQ[i]), i++ ]; L = Append[L, i], {j, 2, 13}]; L (from Vit Planocka)
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CROSSREFS
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A054904, A054905, A054799, A015914, A033560.
Sequence in context: A059664 A108832 A055009 this_sequence A108785 A050507 A054987
Adjacent sequences: A054979 A054980 A054981 this_sequence A054983 A054984 A054985
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KEYWORD
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more,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), May 29 2000
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EXTENSIONS
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More terms from Vit Planocka (planocka(AT)mistral.cz), Sep 22 2003
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