Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A108069
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A108069 Number of ordered pairs (i,j) with i>=1, j>=1 and i!*j! = n. +0
2
1, 2, 0, 1, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; listen)
OFFSET

1,2

LINKS

D. M. Kane, On the number of ways of writing T as a product of factorials, Integers: Electronic Journal of Combinatorial Number Theory, 5 (2005), #A02, 10pp.

FORMULA

Conjecture: max_{n->infinity} a(n) = 4 [Kane]

EXAMPLE

1 = 1!*1!, so a(1) = 1; 2 = 0!*2! = 1!*2! = 2!*0! = 2!*1!, so a(2) = 4.

CROSSREFS

Cf. A108068.

Sequence in context: A112517 A112519 A091728 this_sequence A089734 A035177 A070105

Adjacent sequences: A108066 A108067 A108068 this_sequence A108070 A108071 A108072

KEYWORD

nonn,easy

AUTHOR

njas, Jun 04 2005

EXTENSIONS

More terms from Christian G. Bower (bowerc(AT)usa.net), Jun 04 2005

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 30 22:12 EST 2008. Contains 150989 sequences.


AT&T Labs Research