login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A056692 Number of divisors k of n with GCD(k-1, n) = 1. 0
1, 1, 1, 2, 1, 2, 1, 3, 2, 2, 1, 3, 1, 2, 3, 4, 1, 3, 1, 4, 2, 2, 1, 5, 2, 2, 3, 4, 1, 2, 1, 5, 3, 2, 3, 5, 1, 2, 2, 6, 1, 4, 1, 4, 5, 2, 1, 6, 2, 3, 3, 4, 1, 4, 2, 5, 2, 2, 1, 5, 1, 2, 4, 6, 3, 3, 1, 4, 3, 4, 1, 8, 1, 2, 4, 4, 3, 4, 1, 7, 4, 2, 1, 6, 3, 2, 3, 6, 1, 4, 3, 4, 2, 2, 3, 8, 1, 3, 5, 6, 1, 3, 1, 6, 4 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

EXAMPLE

The positive divisors of 8 are 1, 2, 4, 8. (2-1), (4-1) and (8-1) are relatively prime to 8, so a(8) = 3.

CROSSREFS

Sequence in context: A069248 A008481 A127669 * A039637 A194548 A069157

Adjacent sequences:  A056689 A056690 A056691 * A056693 A056694 A056695

KEYWORD

nonn

AUTHOR

Leroy Quet, Aug 10 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 03:37 EST 2012. Contains 205570 sequences.