id:A068473 - OEIS Search Results

Search: id:A068473

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Numbers n such that phi((prime(n)+1)/2)=sigma(n).

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31, 51, 77, 87, 158, 184, 297, 308, 573, 621, 766, 786, 799, 826, 1167, 1330, 1946, 2030, 2280, 3058, 3213, 5015, 5093, 5271, 5374, 8307, 8813, 9730, 10364, 10557, 11229, 12750, 13462, 14145, 15807, 20606, 23115, 24633, 24795, 26400, 28015 (list; graph; listen)

	OFFSET	`1,1`
	PROGRAM	`(PARI) for(n=2, 45000, if(eulerphi((prime(n)+1)/2)==sigma(n), print1(n, ", ")))`
	CROSSREFS	`Sequence in context: A139896 A004224 A068779 this_sequence A141856 A104332 A045116` `Adjacent sequences: A068470 A068471 A068472 this_sequence A068474 A068475 A068476`
	KEYWORD	`easy,nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 10 2002`

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.

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