|
| |
|
|
A082871
|
|
First component x of pairs (x,y) where x <= y and x!+y! is a square, sorted on x.
|
|
1
| | |
|
|
|
OFFSET
| 1,8
|
|
|
COMMENTS
| Conjecture: the only solutions for x!+y!=n^2 (x <= y) are x=0,0,0,1,1,1,2,4 and y=4,5,7,4,5,7,2,5 respectively.
|
|
|
PROG
| (PARI) sumfactsq(n) = { for(x=0, n, for(y=1, n, z = x!+y!; if(issquare(z), print1(x" ")) ) ) }
|
|
|
CROSSREFS
| Cf. A151819.
Sequence in context: A120313 A176649 * A139627 A166926 A028573 A138758
Adjacent sequences: A082868 A082869 A082870 * A082872 A082873 A082874
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Cino Hilliard (hillcino368(AT)gmail.com), May 25 2003
|
|
|
EXTENSIONS
| Edited and corrected by Farideh Firoozbakht (f.firoozbakht(AT)sci.ui.ac.ir), Jul 07 2009
|
| |
|
|
