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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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3
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434, 104, 80, 182, 427, 1727, 4147, 7163, 42031, 165841, 569257, 2683909, 10040081, 39094849, 155533969, 717519401, 3041377519, 16076525809
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,1
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EXAMPLE
| 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
| 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
| A054904, A054905, A054799, A015914, A033560.
Sequence in context: A198450 A108832 A055009 * A108785 A050507 A145318
Adjacent sequences: A054979 A054980 A054981 * A054983 A054984 A054985
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KEYWORD
| more,nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), May 29 2000
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EXTENSIONS
| More terms from Vit Planocka (planocka(AT)mistral.cz), Sep 22 2003
a(14)-a(19) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Nov 30 2008
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