id:A055654 - OEIS Search Results

Search: id:A055654

Displaying 1-1 of 1 results found.

page 1

Difference between n and the result of "Phi-summation" over unitary divisors of n.

+0
2

0, 0, 0, 1, 0, 0, 0, 3, 2, 0, 0, 3, 0, 0, 0, 7, 0, 4, 0, 5, 0, 0, 0, 9, 4, 0, 8, 7, 0, 0, 0, 15, 0, 0, 0, 15, 0, 0, 0, 15, 0, 0, 0, 11, 10, 0, 0, 21, 6, 8, 0, 13, 0, 16, 0, 21, 0, 0, 0, 15, 0, 0, 14, 31, 0, 0, 0, 17, 0, 0, 0, 37, 0, 0, 12, 19, 0, 0, 0, 35, 26, 0, 0, 21, 0, 0, 0, 33, 0, 20, 0, 23 (list; graph; listen)

	OFFSET	`1,8`
	FORMULA	`a(n)=n-Sum[Phi[u]], where GCD[u, n/u] = 1, i.e. u is unitary divisor of n.`
	EXAMPLE	`Square-free numbers are roots of a(n)=0 equation, while Min n for which a(n)=k is k^2. See also A000188, A008833.`
	CROSSREFS	`Cf. A000188, A008833, A055653, A053570, A053571, A055631, A055632.` `Sequence in context: A033909 A133949 A139808 this_sequence A062787 A131370 A062707` `Adjacent sequences: A055651 A055652 A055653 this_sequence A055655 A055656 A055657`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Jun 07 2000`

page 1

Search completed in 0.002 seconds

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

AT&T Labs Research