id:A057710 - OEIS Search Results

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Positive integers n with exactly 2 aliquot sequence predecessors. In other words, there are exactly two solutions x for which s(x)=n. The function s(x) here refers to the Restricted Divisor Function, the sum of all proper divisors of x.

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4

6, 8, 13, 14, 15, 16, 17, 19, 20, 22, 23, 27, 29, 32, 42, 44, 46, 50, 54, 62, 69, 90, 92, 100, 104, 108, 110, 114, 130, 136, 148, 150, 152, 156, 166, 170, 176, 182, 184, 186, 198, 200, 202, 214, 230, 232, 234, 236, 240, 242, 244, 254, 258, 266, 272, 280, 286 (list; graph; listen)

	OFFSET	`1,1`
	LINKS	`T. D. Noe, Table of n, a(n) for n=1..1000` `Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics (1).` `Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics (2).`
	EXAMPLE	`14 is a member of the sequence because s(22)=14 and s(169)=14 (and because no other integer x satisfies s(x)=14).`
	CROSSREFS	`Cf. A001065, A005114.` `Sequence in context: A077670 A072057 A160133 this_sequence A027706 A047336 A063188` `Adjacent sequences: A057707 A057708 A057709 this_sequence A057711 A057712 A057713`
	KEYWORD	`nonn`
	AUTHOR	`Jack Brennen (jb(AT)brennen.net), Oct 24 2000`

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Last modified November 25 14:49 EST 2009. Contains 167514 sequences.

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