id:A064271 - OEIS Search Results

Search: id:A064271

Displaying 1-1 of 1 results found.

page 1

Numbers n such that sigma(n)-2n is prime.

+0
1

18, 20, 36, 100, 104, 196, 324, 392, 464, 576, 650, 784, 800, 900, 968, 1352, 1936, 1952, 2450, 2500, 3136, 4356, 4624, 5184, 6050, 6400, 9216, 10000, 10404, 10816, 12800, 13456, 14400, 15376, 15488, 16928, 18496, 20000, 20736, 23104, 26912 (list; graph; listen)

	OFFSET	`1,1`
	EXAMPLE	`n=100: sigma(100)-2*100 = 17.`
	PROGRAM	`(PARI) j=[]; for(n=1, 50000, x=sigma(n)-2*n; if(x>0 && isprime(x), j=concat(j, n))); j`
	CROSSREFS	`Sequence in context: A072904 A054279 A036170 this_sequence A113541 A113542 A075865` `Adjacent sequences: A064268 A064269 A064270 this_sequence A064272 A064273 A064274`
	KEYWORD	`easy,nonn`
	AUTHOR	`Jason Earls (zevi_35711(AT)yahoo.com), Sep 23 2001`

page 1

Search completed in 0.003 seconds

Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.

AT&T Labs Research