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Search: id:A091288
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| A091288 |
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Integer solutions x to (q=sigma[x]+sigma[x+1])/sigma[x+x+1], such that q=1, i.e. sigma[x]+sigma[x+1])=sigma[2x+1];sigma[]=A000203. |
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+0
2
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| 1, 4, 646, 1096, 16174, 22891, 64672, 353110, 468970, 515698, 733570, 1317343, 1633213, 1735288, 2026945, 2093506, 2709542, 4413772, 5005825, 5346241, 5388154
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OFFSET
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1,2
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MATHEMATICA
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Do[s=(DivisorSigma[1, n]+DivisorSigma[1, n+1])/ DivisorSigma[1, 2*n+1]; If[Equal[s, 1], Print[n]], {n, 1, 10000000}]
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CROSSREFS
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Cf. A000203, A091287-A091290.
Adjacent sequences: A091285 A091286 A091287 this_sequence A091289 A091290 A091291
Sequence in context: A069641 A079103 A067171 this_sequence A046348 A114765 A059754
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Feb 16 2004
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