id:A070943 - OEIS Search Results

Search: id:A070943

Displaying 1-1 of 1 results found.

page 1

Commuting elements: number of ordered pairs g, h in the group GL(2,Z_n) such that gh = hg.

+0
1

1, 18, 384, 1344, 11520, 6912, 96768, 92160, 303264, 207360, 1584000, 516096, 4402944, 1741824, 4423680, 6094848, 22560768, 5458752, 44323200, 15482880, 37158912, 28512000, 141064704, 35389440, 186000000, 79252992, 226748160 (list; graph; listen)

	OFFSET	`1,2`
	FORMULA	`a(n) = A000252(n) * A062354(n) = n^4 * product (1-1/p^2)(1-1/p) sigma(n)*phi(n) ( where the product is over all the primes p that divide n ).`
	CROSSREFS	`Cf. A000252, A062354.` `Adjacent sequences: A070940 A070941 A070942 this_sequence A070944 A070945 A070946` `Sequence in context: A127585 A086502 A099276 this_sequence A111454 A116421 A005477`
	KEYWORD	`mult,nonn`
	AUTHOR	`Yuval Dekel (dekelyuval(AT)hotmail.com), Sep 12 2003`
	EXTENSIONS	`More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 13 2003`

page 1

Search completed in 0.002 seconds

Last modified October 7 08:31 EDT 2008. Contains 144667 sequences.

AT&T Labs Research