id:A055205 - OEIS Search Results

Search: id:A055205

Displaying 1-1 of 1 results found.

page 1

Number of non-square divisors of n^2.

+0
6

0, 1, 1, 2, 1, 5, 1, 3, 2, 5, 1, 9, 1, 5, 5, 4, 1, 9, 1, 9, 5, 5, 1, 13, 2, 5, 3, 9, 1, 19, 1, 5, 5, 5, 5, 16, 1, 5, 5, 13, 1, 19, 1, 9, 9, 5, 1, 17, 2, 9, 5, 9, 1, 13, 5, 13, 5, 5, 1, 33, 1, 5, 9, 6, 5, 19, 1, 9, 5, 19, 1, 23, 1, 5, 9, 9, 5, 19, 1, 17, 4, 5, 1, 33, 5, 5, 5, 13, 1, 33, 5, 9, 5, 5, 5 (list; graph; listen)

	OFFSET	`1,4`
	LINKS	`T. D. Noe, Table of n, a(n) for n=1..1000`
	FORMULA	`a(n) = A000005(n^2)-A000005(n) because the number of square divisors of n^2 equals the number of divisors of n.`
	EXAMPLE	`n = 8, d(64) = 7 and from the 7 divisors {1,4,16,64} are square and the remaining 3 = a(8). n = 12, d(144) = 15, from which 6 divisors are squares {1,4,9,16,36,144} so a(12) = d(144)-d(12) = 9`
	CROSSREFS	`A000005.` `Sequence in context: A047818 A055972 A079168 this_sequence A161686 A069626 A069359` `Adjacent sequences: A055202 A055203 A055204 this_sequence A055206 A055207 A055208`
	KEYWORD	`nice,nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Jun 19 2000`

page 1

Search completed in 0.002 seconds

Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

AT&T Labs Research