|
Search: id:A118330
|
|
|
| A118330 |
|
a(n-1)*a(n-4) + a(n-2)*a(n-5) + a(n-3)*a(n-6), with a(k<6) = 1. |
|
+0
1
|
|
| 1, 1, 1, 1, 1, 1, 3, 5, 9, 17, 65, 385, 3841, 69087, 4559417, 1759931497, 6761656746177, 467149341275385921, 2129929115299135769778433, 3748529338522222733404780820902657
(list; graph; listen)
|
|
|
OFFSET
|
0,7
|
|
|
COMMENT
|
This is the 3-term analogue of the 2-term recurrence A111288 a(1) = a(2) = a(3) = a(4) = 1. For n>= 5, a(n) = a(n-1)*a(n-3) + a(n-2)*a(n-4). Primes in this sequence include a(n) for n = 6, 7, 9, ... with a(21) and a(22) composite and the sequence growing beyond my ability to efficiently test primality.
|
|
FORMULA
|
a(0) = a(1) = a(2) = a(3) = a(4) = a(5) = 1; for n>5: a(n) = a(n-1)*a(n-4) + a(n-2)*a(n-5) + a(n-3)*a(n-6).
|
|
CROSSREFS
|
Cf. A111288, A111388.
Sequence in context: A096390 A092264 A135729 this_sequence A062221 A074861 A120941
Adjacent sequences: A118327 A118328 A118329 this_sequence A118331 A118332 A118333
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Jonathan Vos Post (jvospost3(AT)gmail.com), May 14 2006
|
|
|
Search completed in 0.002 seconds
|
