|
Search: id:A098480
|
|
|
| A098480 |
|
Expansion of 1/sqrt((1-x)^2-8x^3). |
|
+0
4
|
|
| 1, 1, 1, 5, 13, 25, 65, 181, 445, 1113, 2945, 7685, 19821, 51865, 136513, 358229, 942109, 2487385, 6573825, 17387045, 46066253, 122213913, 324512833, 862511605, 2294698109, 6109933657, 16280439937, 43411979845, 115835462445
(list; graph; listen)
|
|
|
OFFSET
|
0,4
|
|
|
COMMENT
|
1/sqrt((1-x)^2-4rx^3) expands to sum{k=0..floor(n/2), binomial(n-k,k)binomial(n-2k,k)r^k}
|
|
FORMULA
|
a(n)=sum{k=0..floor(n/2), binomial(n-k, k)binomial(n-2k, k)2^k}
|
|
CROSSREFS
|
Cf. A098479, A098481.
Sequence in context: A066885 A057288 A107466 this_sequence A018394 A139595 A008778
Adjacent sequences: A098477 A098478 A098479 this_sequence A098481 A098482 A098483
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Paul Barry (pbarry(AT)wit.ie), Sep 10 2004
|
|
|
Search completed in 0.002 seconds
|
