id:A115165 - OEIS Search Results

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Odd numbers n such that n-1 and n+1 have the same number of distinct prime divisors.

+0
1

3, 11, 13, 19, 21, 23, 25, 27, 35, 37, 39, 45, 47, 49, 51, 53, 55, 57, 73, 75, 81, 87, 93, 95, 97, 99, 105, 107, 117, 123, 131, 135, 139, 143, 145, 147, 155, 159, 161, 163, 165, 169, 177, 181, 193, 195, 201, 207, 213, 215, 217, 221, 225, 229, 239, 243, 249, 259, 265 (list; graph; listen)

	OFFSET	`3,1`
	PROGRAM	`(PARI) g(n) = forstep(x=3, n, 2, p1=omega(x-1); p2=omega(x+1); if(p1==p2, print(x", ")))`
	CROSSREFS	`Sequence in context: A158296 A160025 A045427 this_sequence A050583 A045428 A103835` `Adjacent sequences: A115162 A115163 A115164 this_sequence A115166 A115167 A115168`
	KEYWORD	`easy,nonn`
	AUTHOR	`Cino Hilliard (hillcino368(AT)gmail.com), Mar 03 2006`

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.

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