|
Search: id:A122069
|
|
|
| A122069 |
|
a(0)=1, a(1)=3, a(n)=3*a(n-1)+9*a(n-2) for n>1. |
|
+0
1
|
|
| 1, 3, 18, 81, 405, 1944, 9477, 45927, 223074, 1082565, 5255361, 25509168, 123825753, 601059771, 2917611090, 14162371209, 68745613437, 333698181192, 1619805064509, 7862698824255, 38166342053346, 185263315578333
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
FORMULA
|
a(n)=3^n*Fibonacci(n+1)=3^n*A000045(n+1) . a(n)=Sum_{k, 0<=k<=n}2^k*A016095(n,k) . G.f.:1/(1-3*x-9*x^2) a(n+1)/a(n)->3*((1+sqrt(5))/2 if n ->infinity.
a(n)=A099012(n+1). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 02 2008]
|
|
CROSSREFS
|
Adjacent sequences: A122066 A122067 A122068 this_sequence A122070 A122071 A122072
Sequence in context: A036290 A078904 A099012 this_sequence A103897 A119424 A037295
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 15 2006
|
|
EXTENSIONS
|
Corrected by T. D. Noe (noe(AT)sspectra.com), Nov 07 2006
|
|
|
Search completed in 0.002 seconds
|
