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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108466 Number of factorizations of (n,n) into pairs (i,j) with i,j>1. 2
1, 1, 1, 2, 1, 3, 1, 4, 2, 3, 1, 11, 1, 3, 3, 9, 1, 11, 1, 11, 3, 3, 1, 35, 2, 3, 4, 11, 1, 25, 1, 20, 3, 3, 3, 55, 1, 3, 3, 35, 1, 25, 1, 11, 11, 3, 1, 106, 2, 11, 3, 11, 1, 35, 3, 35, 3, 3, 1, 132, 1, 3, 11, 45, 3, 25, 1, 11, 3, 25, 1, 222, 1, 3, 11, 11, 3, 25, 1, 106, 9, 3, 1, 132, 3, 3 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

COMMENTS

(a,b)*(x,y)=(a*x,b*y).

a(n) depends only on prime signature of n (cf. A025487). So a(24) = a(375) since 24=2^3*3 and 375=3*5^3 both have prime signature (3,1).

CROSSREFS

Cf. A108461. Main diagonal of A108465. a(A025487)=A108467. a(p^k)=A108469(k). a(A002110)=A023997.

Sequence in context: A002033 A074206 A173801 * A200780 A087145 A194943

Adjacent sequences:  A108463 A108464 A108465 * A108467 A108468 A108469

KEYWORD

nonn

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Jun 03 2005

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 16 21:51 EST 2012. Contains 205978 sequences.