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A091292
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Numbers n such that the following quotient is an integer: (sigma[n]+sigma[n+1]+sigma[n+2])/sigma[3n+3], i.e. sum[sigma[j]]/sigma[sum[j]] for 3 terms summed up is integer.
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0
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424, 2134, 20154, 23954, 27344, 27584, 37414, 45154, 74874, 89654, 503810, 1327292, 1910174, 8976614, 13954744, 17386316, 20920074, 22436224, 22937784, 23253068, 29705192, 70524530, 78617972, 81607504, 85815924, 94163306
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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MATHEMATICA
| g[x_, k_] := Apply[Plus, Table[sg[x+j], j, 0, k-1}]]/ sg[Apply[Plus, Table[x+j, j, 0, k-1}]]] Do[s=g[n, 3]; If[IntegerQ[s], Print[n]], n, 1, 10000000}]
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CROSSREFS
| Cf. A000203, A091287-A091293.
Sequence in context: A091293 A134218 A202772 * A184766 A160098 A203343
Adjacent sequences: A091289 A091290 A091291 * A091293 A091294 A091295
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Feb 17 2004
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EXTENSIONS
| a(15)-a(26) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 01 2009
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