|
Search: id:A108404
|
|
|
| A108404 |
|
Expansion of (1-4x)/(1-8x+11x^2). |
|
+0
4
|
|
| 1, 4, 21, 124, 761, 4724, 29421, 183404, 1143601, 7131364, 44471301, 277325404, 1729418921, 10784771924, 67254567261, 419404046924, 2615432135521, 16310012568004, 101710347053301, 634272638178364, 3955367287840601
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Binomial transform of A098648. Second binomial transform of A001077. Third binomial transform of A084057. 4th binomial transform of (1, 0, 5, 0, 25, 0, 125, 0, 625, 0, 3125, ...).
|
|
FORMULA
|
E.g.f.: exp(4x)cosh(sqrt(5)x).
a(n) = 8a(n-1) - 11a(n-2), a(0) = 1, a(1) = 4.
a(n) = ((4+sqrt(5))^n + (4-sqrt(5))^n)/2.
a(n+1)/a(n) converges to 4 + sqrt(5) = 6.2360679774997896964...
|
|
CROSSREFS
|
Cf. A001077, A084057, A098648.
Sequence in context: A001888 A103769 A003014 this_sequence A115136 A101478 A153291
Adjacent sequences: A108401 A108402 A108403 this_sequence A108405 A108406 A108407
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jul 04 2005
|
|
|
Search completed in 0.002 seconds
|
