|
Search: id:A158445
|
|
| |
|
| 30, 105, 230, 405, 630, 905, 1230, 1605, 2030, 2505, 3030, 3605, 4230, 4905, 5630, 6405, 7230, 8105, 9030, 10005, 11030, 12105, 13230, 14405, 15630, 16905, 18230, 19605, 21030, 22505, 24030, 25605, 27230, 28905, 30630, 32405, 34230, 36105
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
If A=[A158445] 25*n.^2+5 (n>0, 30, 105, 230,.,); Y=[A005843] 2*n (n>0, 2, 4, 6,.,); X = [A158187] 10*n^2+1 (n>0, 11, 41,91, .,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 11^2-30*2^2=1; 41^2-105*4^2=1; 91^2-230*6^2=1.
|
|
LINKS
|
Edward Everett Withford, Pell Equation
Vincenzo Librandi, X^2-AY^2=1
Philippe Chevanne, Pell Equation
|
|
FORMULA
|
a(n)=25*n^2+5 (n>0)
|
|
EXAMPLE
|
For n=1, a(1)=30; n=2, a(2)=105 n=3, a(3)=230
|
|
CROSSREFS
|
Cf. A005843, A158187
Sequence in context: A043998 A101056 A081370 this_sequence A046301 A043466 A044281
Adjacent sequences: A158442 A158443 A158444 this_sequence A158446 A158447 A158448
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 19 2009
|
|
|
Search completed in 0.002 seconds
|
