A054973 - OEIS

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A054973

Number of numbers whose divisors sum to n.

1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 2, 1, 1, 1, 0, 0, 2, 0, 1, 0, 0, 0, 3, 0, 0, 0, 1, 0, 1, 2, 2, 0, 0, 0, 1, 0, 1, 1, 1, 0, 3, 0, 1, 0, 0, 0, 3, 0, 0, 0, 0, 0, 2, 0, 2, 1, 0, 0, 3, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 5, 0, 1, 0, 0, 0, 1, 0, 2, 0, 0, 0, 3, 0, 0, 0, 0, 0, 3, 1, 0, 1, 0, 0, 4, 0 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,12`
	COMMENTS	`a(n) = frequency of values n in A000203(m), where A000203(m) = sum of divisors of m. a(n) >= 1 for such n that A175192(n) = 1, a(n) >= 1 if A000203(m) = n for any m. a(n) = 0 for such n that A175192(n) = 0, a(n) = 0 if A000203(m) = n has no solution. [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Mar 01 2010]`
	LINKS	`T. D. Noe, Table of n, a(n) for n=1..10000`
	EXAMPLE	`a(12)=2 since 11 has factors 1 and 11 with 1+11=12 and 6 has factors 1, 2, 3 and 6 with 1+2+3+6=12`
	CROSSREFS	`Cf. A000203, A002191, A007609.` `Sequence in context: A111405 A089053 A068462 * A030351 A188921 A072617` `Adjacent sequences: A054970 A054971 A054972 * A054974 A054975 A054976`
	KEYWORD	`nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), May 16 2000`

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Last modified February 16 06:08 EST 2012. Contains 205860 sequences.