|
Search: id:A157953
|
|
| |
|
| 80, 322, 726, 1292, 2020, 2910, 3962, 5176, 6552, 8090, 9790, 11652, 13676, 15862, 18210, 20720, 23392, 26226, 29222, 32380, 35700, 39182, 42826, 46632, 50600, 54730, 59022, 63476, 68092, 72870, 77810, 82912, 88176, 93602, 99190, 104940
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
If A=[A157953] 81*n.^2-n (80, 322, 726, ,.,); Y=[A010857] 18 (18, 18, 18, ,.,); X=[A157954] 162*n-1 (161, 323, 485, .,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 161^2-80 *18^2=1; 323^2-322*18^2=1; 485^2-726*18^2=1.
|
|
LINKS
|
Edward Everett Withford, Pell Equation
Vincenzo Librandi, X^2-AY^2=1
Wolfram MathWorld, Pell Equation
|
|
FORMULA
|
a(n)=81*n^2-n (n>0)
|
|
EXAMPLE
|
For n=1, a(1)=80; n=2, a(2)=322; n=3, a(3)=726
|
|
CROSSREFS
|
Vf. A010857, A157954
Sequence in context: A044793 A157912 A057441 this_sequence A045666 A045657 A085774
Adjacent sequences: A157950 A157951 A157952 this_sequence A157954 A157955 A157956
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 10 2009
|
|
|
Search completed in 0.002 seconds
|
