id:A063806 - OEIS Search Results

Search: id:A063806

Displaying 1-1 of 1 results found.

page 1

Numbers with a prime number of proper divisors.

+0
1

4, 6, 8, 9, 10, 12, 14, 15, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 40, 42, 44, 45, 46, 49, 50, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 82, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 102, 104 (list; graph; listen)

	OFFSET	`1,1`
	EXAMPLE	`15 has three proper divisors {1,3,5} and so is on the list; 16 has four {1,2,4,8} and so is not; 17 has one {1} and so is not; 18 has five {1,2,3,6,9} and so is.`
	CROSSREFS	`A subset of A002808. Cf. A009087, A032741.` `Sequence in context: A117098 A077136 A098216 this_sequence A063989 A117097 A077135` `Adjacent sequences: A063803 A063804 A063805 this_sequence A063807 A063808 A063809`
	KEYWORD	`nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Aug 20 2001`

page 1

Search completed in 0.002 seconds

Last modified July 26 13:41 EDT 2008. Contains 142293 sequences.

AT&T Labs Research