login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A319589 A 3 X 3 magic square with five square entries, read by rows. 1
34969, 83521, 7585, 14641, 42025, 69409, 76465, 529, 49081 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Some magic squares of order 3 with five square entries have this parametric form:
|-----------------------|-----------------------|-----------------------|
| (x*y)^2 | y^4 |sqrt(z)*(3*x^2 - y^2)/2|
|-----------------------|-----------------------|-----------------------|
| x^4 | z | 2*z - x^4 |
|-----------------------|-----------------------|-----------------------|
|sqrt(z)*(3*y^2 - x^2)/2| 2*z - y^4 | 2*z - (x*y)^2 |
|-----------------------|-----------------------|-----------------------|
where z = (x^2 + y^2)^2/4, x and y are integers such that (x^4 - y^4 + 2*(x*y)^2)/2 is a square (e.g., x = 11 and y = 17; x = 5337 and y = 6257).
This sequence presents the magic square belonging to this family and having the smallest possible magic sum (S = 126075).
LINKS
EXAMPLE
The magic square is
+-------+-------+-------+
| 187^2 | 17^4 | 7585 |
+-------+-------+-------+
| 11^4 | 205^2 | 69409 |
+-------+-------+-------+
| 76465 | 23^2 | 49081 |
+-------+-------+-------+
CROSSREFS
Sequence in context: A257755 A230976 A085847 * A237065 A233631 A281886
KEYWORD
nonn,fini,full,tabf
AUTHOR
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 31 19:41 EDT 2023. Contains 363068 sequences. (Running on oeis4.)