id:A105571 - OEIS Search Results

Search: id:A105571

Displaying 1-1 of 1 results found.

page 1

Numbers m such that m-2 and m+2 have 2 prime factors.

+0
3

8, 12, 23, 24, 36, 37, 53, 60, 67, 84, 89, 93, 113, 117, 120, 121, 131, 143, 144, 157, 185, 203, 204, 207, 211, 215, 216, 217, 219, 251, 276, 289, 293, 297, 300, 301, 303, 307, 321, 325, 337, 360, 363, 379, 384, 393, 396, 405, 409, 413, 415, 449, 456, 471, 480 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`A001222(a(n)-2) = A001222(a(n)+2) = 2;`
	MATHEMATICA	`q=2; lst={}; Do[If[Plus@@Last/@FactorInteger[n-q]==q&&Plus@@Last/@FactorInteger[n+q]==q, AppendTo[lst, n]], {n, 7!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Feb 01 2009]`
	CROSSREFS	`Cf. A014574, A105572, A105573.` `Sequence in context: A001749 A072843 A072902 this_sequence A141616 A088525 A054735` `Adjacent sequences: A105568 A105569 A105570 this_sequence A105572 A105573 A105574`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 14 2005`

page 1

Search completed in 0.002 seconds

Last modified November 27 22:38 EST 2009. Contains 167602 sequences.

AT&T Labs Research