Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A120336
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A120336 Number of solutions (x,y) of Diophantine equation y^2 = x*(a^N - x)*( b^N + x) ( Weierstrass elliptic equation) with a and b legs in primitive Pythagorean triangles and N = 2. Sequence ordered in increasing values of leg "a". +0
1
1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1 (list; graph; listen)
OFFSET

1,5

COMMENT

Triads a = 3 b = 4 c = 5 and a = 4 b = 3 c = 5 provide different results for (x,y).

EXAMPLE

First primitive Pythagorean triad: 3, 4, 5

Weierstrass equation. y^2 = x*( 3^2 -x)*( 4^2 + x)

Unique integer solution (x,y) = (4,20)

First element in the sequence = 1

Fifth primitive Pythagorean triad: 8, 15, 17

Integer solutions (x,y) = (15, 420) and (30, 510)

Fifth element in the sequence = 2

MAPLE

# a, b, c primitive Pythagorean triad n_sol:=0; for x from 1 by 1 to a^2 do y2:= x*( a^2 - x)*( x+ b^2); if ((floor(sqrt(y2)))^2=y2) n_sol:=n_sol+1; fi; print(n_sol) ; od;

CROSSREFS

Cf. A009003, A020884, A120210, A120211, A120212, A120213.

Sequence in context: A165633 A117456 A030621 this_sequence A039738 A075774 A078572

Adjacent sequences: A120333 A120334 A120335 this_sequence A120337 A120338 A120339

KEYWORD

nonn

AUTHOR

Giorgio Balzarotti and Paolo P. Lava (greenblue(AT)tiscali.it), Jun 22 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 December 19 12:50 EST 2009. Contains 171053 sequences.


AT&T Labs Research