id:A051464 - OEIS Search Results

Search: id:A051464

Displaying 1-1 of 1 results found.

page 1

Number of divisors of 4*(2^n-1) + 1.

+0
1

2, 2, 2, 2, 4, 4, 2, 2, 4, 2, 4, 2, 4, 6, 4, 4, 16, 2, 4, 2, 4, 2, 4, 8, 12, 8, 2, 4, 8, 4, 4, 4, 4, 4, 4, 8, 8, 4, 8, 16, 8, 4, 8, 8, 6, 16, 8, 8, 8, 16, 8, 4, 32, 32, 8, 4, 8, 4, 4, 8, 16, 8, 8, 16, 48, 16, 16, 8, 4, 16, 4, 16, 16, 8, 8, 8, 16, 16, 8, 16, 16, 8, 16, 8, 48, 192, 8, 8, 16, 4, 8, 2 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Create a table with tau(2^n-1) as the first row (A046801) and tau(m) as the first column (A000005). The second column is tau(A004760) and so on. Rows 2, 3 and 4 are easily described in terms of row 1. This sequence is row 5.`
	FORMULA	`a[ n ] = DivisorSigma [ 0, 4*(2^n -1)+1 ] ]`
	CROSSREFS	`Sequence in context: A155904 A125913 A122386 this_sequence A060632 A151565 A160407` `Adjacent sequences: A051461 A051462 A051463 this_sequence A051465 A051466 A051467`
	KEYWORD	`nonn`
	AUTHOR	`Edwin D. Evans, eevans2(AT)pacbell.net`

page 1

Search completed in 0.002 seconds

Last modified November 27 14:50 EST 2009. Contains 167570 sequences.

AT&T Labs Research