|
Search: id:A158394
|
|
| |
|
| 727, 2912, 6555, 11656, 18215, 26232, 35707, 46640, 59031, 72880, 88187, 104952, 123175, 142856, 163995, 186592, 210647, 236160, 263131, 291560, 321447, 352792, 385595, 419856, 455575, 492752, 531387, 571480, 613031, 656040, 700507, 746432
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
If A=[A158394] 729*n.^2-2*n (n>0, 727, 2912, 6555,.,); Y=[A010866] 27 (27, 27, 27, ,.,); X=[A158395] 729*n-1 (n>0, 728, 1457, 2186, .,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 728^2-727*27^2=1; 1457^2-2912*27^2=1; 2186^2-6555*27^2=1.
|
|
LINKS
|
Edward Everett Withford, Pell Equation
Vincenzo Librandi, X^2-AY^2=1
Wolfram MathWorld, Pell Equation
|
|
FORMULA
|
a(n)=729*n^2-2*n (n>0)
|
|
EXAMPLE
|
For n=1, a(1)=727; n=2, a(2)=2912; n=3,a(3)=6555
|
|
CROSSREFS
|
Cf. A010866, A158395
Sequence in context: A103170 A153215 A129117 this_sequence A038600 A157430 A094733
Adjacent sequences: A158391 A158392 A158393 this_sequence A158395 A158396 A158397
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 18 2009
|
|
|
Search completed in 0.002 seconds
|
