id:A117288 - OEIS Search Results

Search: id:A117288

Displaying 1-1 of 1 results found.

page 1

Numbers n for which the cototient n-phi(n) is a octagonal number.

+0
1

1, 2, 3, 5, 7, 11, 12, 13, 14, 16, 17, 19, 23, 29, 31, 37, 41, 43, 45, 47, 53, 57, 59, 61, 67, 71, 73, 76, 79, 83, 85, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 144, 149, 151, 157, 160, 163, 167, 173, 176, 179, 181, 184, 188, 191, 193, 197, 199, 211, 223 (list; graph; listen)

	OFFSET	`0,2`
	EXAMPLE	`45 is in the sequence because 45-phi(45)=21, which is a octagonal number.`
	CROSSREFS	`Cf. A000567.` `Sequence in context: A060264 A104192 A104193 this_sequence A117283 A137923 A131930` `Adjacent sequences: A117285 A117286 A117287 this_sequence A117289 A117290 A117291`
	KEYWORD	`nonn`
	AUTHOR	`Luc Stevens (lms022(AT)yahoo.com), Apr 23 2006`

page 1

Search completed in 0.002 seconds

Last modified November 18 20:14 EST 2008. Contains 147244 sequences.

AT&T Labs Research