id:A100587 - OEIS Search Results

Search: id:A100587

Displaying 1-1 of 1 results found.

page 1

Number of non-empty subsets of divisors of n.

+0
2

1, 3, 3, 7, 3, 15, 3, 15, 7, 15, 3, 63, 3, 15, 15, 31, 3, 63, 3, 63, 15, 15, 3, 255, 7, 15, 15, 63, 3, 255, 3, 63, 15, 15, 15, 511, 3, 15, 15, 255, 3, 255, 3, 63, 63, 15, 3, 1023, 7, 63, 15, 63, 3, 255, 15, 255, 15, 15, 3, 4095, 3, 15, 63, 127, 15, 255, 3, 63, 15, 255, 3, 4095, 3 (list; graph; listen)

	OFFSET	`1,2`
	FORMULA	`a[n]=-1+2^tau[n], tau[n]=DivisorSigma[0, n]=A000005[n]`
	EXAMPLE	`For all prime numbers p, a[p]=3, since those subsets are {{1,p},{1},{p}}.`
	CROSSREFS	`Cf. A100371, A000005, A066781.` `Adjacent sequences: A100584 A100585 A100586 this_sequence A100588 A100589 A100590` `Sequence in context: A122978 A119347 A062402 this_sequence A099282 A002937 A085870`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Dec 01 2004`

page 1

Search completed in 0.002 seconds

Last modified October 7 08:31 EDT 2008. Contains 144667 sequences.

AT&T Labs Research