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A340713
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Numbers k such that sigma(k+1) = 4 * sigma(k).
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3
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37033919, 141162839, 264995639, 596672999, 606523679, 630777839, 791656319, 920424119, 1060332839, 1379454719, 1954690919, 3799661039, 4024838999, 4633959959, 5393988599, 5935994063, 8831231639, 9866482079, 11237657759, 11273710139, 12266364599, 14440498379, 14952625379
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OFFSET
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1,1
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LINKS
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PROG
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(PARI) isok(k) = sigma(k+1) == 4*sigma(k); \\ Michel Marcus, Jan 18 2021
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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