id:A066025 - OEIS Search Results

Search: id:A066025

Displaying 1-1 of 1 results found.

page 1

Numbers n such that GCD(EulerPhi(n),EulerPhi(n+1)) > n.

+0
1

5, 12, 14, 70, 88, 125, 180, 204, 206, 220, 957, 1253, 1334, 1364, 1634, 1673, 1750, 1888, 1919, 2685, 2759, 2958, 2974, 3127, 4364, 5191, 7615, 8142, 8632, 9114, 11219, 12000, 12035, 14664, 14841, 18414, 18762, 18873, 19358, 20118 (list; graph; listen)

	OFFSET	`1,1`
	EXAMPLE	`GCD(EulerPhi(12),EulerPhi(13)) = GCD(28,14) = 14 > 12.`
	MATHEMATICA	`Select[Range[1, 10^5], GCD[DivisorSigma[1, # ], DivisorSigma[ 1, # + 1]] > # &]`
	CROSSREFS	`Cf. A000010.` `Sequence in context: A014156 A114073 A037007 this_sequence A009824 A087090 A056713` `Adjacent sequences: A066022 A066023 A066024 this_sequence A066026 A066027 A066028`
	KEYWORD	`nonn`
	AUTHOR	`Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 11 2001`

page 1

Search completed in 0.002 seconds

Last modified July 25 07:41 EDT 2008. Contains 142293 sequences.

AT&T Labs Research