A065205 - OEIS

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A065205

Number of subsets of proper divisors of n that sum to n.

0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 1, 0, 0, 0, 5, 0, 0, 0, 1, 0, 3, 0, 0, 0, 0, 0, 7, 0, 0, 0, 3, 0, 2, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 3, 0, 2, 0, 0, 0, 34, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 31, 0, 0, 0, 0, 0, 1, 0, 6, 0, 0, 0, 25, 0, 0, 0, 1, 0, 23, 0, 0, 0, 0, 0, 21, 0, 0, 0, 2 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,12`
	COMMENTS	`Deficient and weird numbers have a(n)=0, perfect numbers and others (see A064771) have a(n)=1.`
	LINKS	`T. D. Noe, Table of n, a(n) for n=1..1000`
	EXAMPLE	`{1,4,5,10} is the only subset of proper divisors of 20 that sum to 20, so a(20)=1.`
	CROSSREFS	`Cf. A064771.` `a(n) = A033630(n) - 1.` `Sequence in context: A143840 A028649 A097798 * A036272 A083339 A133827` `Adjacent sequences: A065202 A065203 A065204 * A065206 A065207 A065208`
	KEYWORD	`nonn`
	AUTHOR	`Jonathan Ayres (jonathan.ayres(AT)btinternet.com), Oct 19 2001`
	EXTENSIONS	`More terms and additional comments from Jud McCranie (JudMcCranie(AT)ugaalum.uga.edu), Oct 21 2001`

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Last modified February 13 13:13 EST 2012. Contains 205482 sequences.