|
Search: id:A072557
|
|
|
| A072557 |
|
Let w(n) be defined by the following recurrence: w(1)=w(2)=w(3)=1, w(n)=(w(n-1)*w(n-2)+(w(n-1)+w(n-2))/3) / w(n-3); sequence gives values of n such that w(n) is an integer. |
|
+0
4
|
|
| 5, 11, 16, 17, 18, 23, 29, 34, 35, 36, 41, 47, 52, 53, 54, 59, 65, 70, 71, 72, 77, 83, 88, 89, 90, 95, 101, 106, 107, 108, 113, 119, 124, 125, 126, 131, 137, 142, 143, 144, 149, 155, 160, 161, 162, 167, 173, 178, 179, 180, 185, 191, 196, 197, 198, 203, 209, 214
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Denominators of w(k) are = 1,3 or 9 only.
|
|
FORMULA
|
lim n -> infinity a(n)/n = 18/5. sequence contains numbers of form (5+18k), (11+18k), (16+18k), (17+18k), (18+18k) k>=0.
|
|
EXAMPLE
|
First 11 values of w(n) are 5/3, 23/9, 17/3, 31/3, 25, 143/3, 353/3, 2039/9, 1685/3, 3251/3, 2689 which are integers fo k= 5 and 11 hence a(1)=5 a(2)=11
|
|
CROSSREFS
|
Cf. A072560, A072561.
Adjacent sequences: A072554 A072555 A072556 this_sequence A072558 A072559 A072560
Sequence in context: A137010 A137007 A137012 this_sequence A035108 A022136 A042385
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 06 2002
|
|
|
Search completed in 0.002 seconds
|
