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A067282 Numbers n such that phi(n)+phi(n+1) divides sigma(n)+sigma(n+1). 2
1, 5, 52, 55, 185, 506, 551, 590, 644, 667, 707, 2285, 2587, 2758, 7551, 10366, 11336, 11564, 11798, 12750, 16616, 16703, 16764, 17383, 18239, 24350, 24415, 26586, 33263, 35541, 40382, 63248, 76247, 76622, 92379, 95069, 97341, 106312, 111388 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Presumably the ratio (sigma(n)+sigma(n+1))/(phi(n)+phi(n+1)) can be arbitrarily large (Labos)

CROSSREFS

Sequence in context: A003515 A022501 A134097 * A045539 A081075 A193809

Adjacent sequences:  A067279 A067280 A067281 * A067283 A067284 A067285

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 23 2002

EXTENSIONS

More terms from Labos E. (labos(AT)ana.sote.hu), Sep 17 2004

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Last modified February 14 17:41 EST 2012. Contains 205651 sequences.