Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A115878
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A115878 a(n) is the number of positive solutions of the diophantine equation x^2=y(y+n). +0
4
0, 0, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 4, 2, 1, 2, 1, 1, 4, 1, 1, 4, 2, 1, 3, 1, 1, 4, 1, 3, 4, 1, 4, 2, 1, 1, 4, 4, 1, 4, 1, 1, 7, 1, 1, 7, 2, 2, 4, 1, 1, 3, 4, 4, 4, 1, 1, 4, 1, 1, 7, 4, 4, 4, 1, 1, 4, 4, 1, 7, 1, 1, 7, 1, 4, 4, 1, 7, 4, 1, 1, 4, 4, 1, 4, 4, 1, 7, 4, 1, 4, 1, 4, 10, 1, 2, 7, 2, 1, 4 (list; graph; listen)
OFFSET

1,9

EXAMPLE

a(15)=4 since there are 4 solutions (x,y) to x^2=y(y+15), namely (4,1), (10,5), (18, 12), and (56, 49).

CROSSREFS

Cf. A067721, A115879, A115880, A115881.

Sequence in context: A132068 A129192 A062540 this_sequence A127125 A114171 A140345

Adjacent sequences: A115875 A115876 A115877 this_sequence A115879 A115880 A115881

KEYWORD

nonn

AUTHOR

Giovanni Resta (g.resta(AT)iit.cnr.it), Feb 02 2006

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 August 19 23:53 EDT 2008. Contains 142930 sequences.


AT&T Labs Research