|
Search: id:A020727
|
|
|
| A020727 |
|
Pisot sequence P(2,7): a(0)=2, a(1)=7, thereafter a(n+1) is the nearest integer to a(n)^2/a(n-1). |
|
+0
5
|
|
| 2, 7, 24, 82, 280, 956, 3264, 11144, 38048, 129904, 443520, 1514272, 5170048, 17651648, 60266496, 205762688, 702517760, 2398545664, 8189147136, 27959497216, 95459694592, 325919783936, 1112759746560, 3799199418368, 12971278180352, 44286713884672
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
Also Pisot sequence T(2,7). - R. K. Guy (rkg(AT)cpsc.ucalgary.ca)
|
|
FORMULA
|
It appears that a(n) = 4a(n-1) - 2a(n-2) (holds at least up to n = 1000).
|
|
CROSSREFS
|
Subsequence of A003480. See A008776 for definitions of Pisot sequences.
Sequence in context: A099463 A021000 A003480 this_sequence A088854 A000777 A144170
Adjacent sequences: A020724 A020725 A020726 this_sequence A020728 A020729 A020730
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
David W. Wilson (davidwwilson(AT)comcast.net)
|
|
EXTENSIONS
|
Edited by N. J. A. Sloane, Aug 17 2009 at the suggestion of R. J. Mathar.
|
|
|
Search completed in 0.002 seconds
|
