|
Search: id:A157730
|
|
|
| A157730 |
|
a(n)=441*n^2-488*n+135 (n>0) |
|
+0
3
|
|
| 88, 923, 2640, 5239, 8720, 13083, 18328, 24455, 31464, 39355, 48128, 57783, 68320, 79739, 92040, 105223, 119288, 134235, 150064, 166775, 184368, 202843, 222200, 242439, 263560, 285563, 308448, 332215, 356864, 382395, 408808, 436103, 464280
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
If A=[A157730] 441*n.^2-488*n+135 (88, 923, 2640, 5239,..,); Y=[A157731] 18522*n- 10248 (8274, 26796, 45318..,); X=[A157732] 388962*n^2-430416*n + 119071 (77617, 814087, 2328481,..,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 77617^2-88 * 8274^2=1; 814087^2-923*26796^2=1; 2328481^2-2640*45318^2=1.
|
|
LINKS
|
Edward Everett Withford, Pell Equation
Wolfram MathWorld, Pell Equation
Vincenzo Librandi, X^2-AY^2=1
|
|
FORMULA
|
a(n)=441*n^2-488*n+135 (n>0)
|
|
EXAMPLE
|
For n=1, a(1)=88; n=2, a(2)=923; n=3, a(3)=2640
|
|
CROSSREFS
|
Cf. 157731, A157732
Sequence in context: A136933 A136958 A137049 this_sequence A055749 A107422 A093288
Adjacent sequences: A157727 A157728 A157729 this_sequence A157731 A157732 A157733
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 05 2009
|
|
|
Search completed in 0.002 seconds
|
