|
Search: id:A106328
|
|
|
| A106328 |
|
Numbers j such that 8*(j^2) + 9 = k^2 for some positive number k. |
|
+0
3
|
|
| 0, 3, 18, 105, 612, 3567, 20790, 121173, 706248, 4116315, 23991642, 139833537, 815009580, 4750223943, 27686334078, 161367780525, 940520349072, 5481754313907, 31950005534370, 186218278892313, 1085359667819508, 6325939728024735
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
The ratio k(n) /(2*j(n)) tends to sqrt(2) as n increases.
|
|
LINKS
|
Tanya Khovanova, Recursive Sequences
|
|
FORMULA
|
j(1)=0, j(2)=3 then j(n)=6*j(n-1)-j(n-2)
j(n) = ((3+2*sqrt(2))^(n-1) - (3-2*sqrt(2))^(n-1))*3/4/sqrt(2). - Max Alekseyev (maxal(AT)cs.ucsd.edu), Jan 11 2007
|
|
CROSSREFS
|
Cf. A103328.
Equals (3/4) A005319(n-1).
Adjacent sequences: A106325 A106326 A106327 this_sequence A106329 A106330 A106331
Sequence in context: A009021 A124408 A136779 this_sequence A007277 A025595 A137962
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Pierre CAMI (pierrecami(AT)tele2.fr), Apr 29 2005
|
|
EXTENSIONS
|
More terms from Max Alekseyev (maxal(AT)cs.ucsd.edu), Jan 11 2007
|
|
|
Search completed in 0.002 seconds
|
