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 A186273 a(n) is the least number k having exactly n representations as m + sigma(m), where sigma(m) is the sum of the divisors of m. 0
 2, 11, 95, 3623, 2363, 6143, 21263, 89303, 202703, 472973, 493763, 1013513, 3986483, 3306713, 2364863, 21283763, 19932413, 29391863, 74887313, 98679263, 87499913, 134797163, 201013313, 267843713, 560472413, 775337063, 361823963, 673985813 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE For the n-th term, the n solutions are 2     {1} 11    {4, 5} 95    {32, 39, 47} 3623  {1687, 1727, 1751, 1811} 2363  {1011, 1099, 1139, 1147, 1181} 6143  {2048, 2631, 2863, 2951, 2983, 3007} 21263 {9111, 10231, 10319, 10447, 10471, 10519, 10631} 89303 {38271, 41671, 42991, 43367, 44287, 44311, 44431, 44651} MATHEMATICA nn=1000000; t=Table[n+DivisorSigma[1, n], {n, nn}]; t2=Select[t, # <= 2*nn+1&]; ts=Sort[Tally[t2]]; u=Union[Transpose[ts][[2]]]; c=Complement[Range[Max[u]], u]; If[c != {}, u=Range[c[[1]]-1]]; Table[Select[ts, #[[2]] == n &, 1][[1, 1]], {n, u}] CROSSREFS Cf. A007368 (smallest k such that sigma(x) = k has exactly n solutions). Sequence in context: A266834 A131407 A197994 * A332239 A261886 A245895 Adjacent sequences:  A186270 A186271 A186272 * A186274 A186275 A186276 KEYWORD nonn AUTHOR J. M. Bergot, Feb 16 2011 EXTENSIONS Corrected and extended by T. D. Noe, Feb 16 2011 a(13)-a(28) from Donovan Johnson, Feb 17 2011 STATUS approved

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Last modified July 29 22:13 EDT 2021. Contains 346346 sequences. (Running on oeis4.)