id:A068355 - OEIS Search Results

Search: id:A068355

Displaying 1-1 of 1 results found.

page 1

Odd n such that sigma(n)*tau(n)>prime(2*n) where sigma(n) is the sum of divisors of n and tau(n) the number of divisors of n = A000005(n).

+0
1

45, 105, 135, 165, 195, 225, 315, 405, 495, 525, 567, 585, 675, 693, 735, 765, 819, 825, 855, 945, 975, 1035, 1071, 1125, 1155, 1197, 1215, 1275, 1287, 1305, 1323, 1365, 1395, 1425, 1449, 1485, 1575, 1617, 1665, 1683, 1701, 1725, 1755, 1785, 1815 (list; graph; listen)

	OFFSET	`1,1`
	PROGRAM	`PARI: for(n=1, 2200, if(sigma(n)numdiv(n)(1-(-1)^n)/2>prime(2*n), print1(n, ", ")))`
	CROSSREFS	`Adjacent sequences: A068352 A068353 A068354 this_sequence A068356 A068357 A068358` `Sequence in context: A124974 A063069 A067828 this_sequence A043442 A044232 A044613`
	KEYWORD	`easy,nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 28 2002`

page 1

Search completed in 0.002 seconds

Last modified October 15 20:12 EDT 2008. Contains 145099 sequences.

AT&T Labs Research