|
| |
|
|
A155179
|
|
a(n)=4*a(n-1)+a(n-2), n>2 ; a(0)=1, a(1)=3, a(2)=12 .
|
|
2
| |
|
|
1, 3, 12, 51, 216, 915, 3876, 16419, 69552, 294627, 1248060, 5286867, 22395528, 94868979, 401871444, 1702354755, 7211290464, 30547516611, 129401356908, 548152944243, 2322013133880, 9836205479763, 41666835052932
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| A155179 == Integer numbers of Fibonacci Number * (3/2). [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 25 2009]
|
|
|
FORMULA
| G.f.: (1-x-x^2)/((1-4*x-x^2).
a(n) = (3/2)*((2-sqrt(5))^(n-1)+(2+sqrt(5))^(n-1))+(3/5)*sqrt(5)*((2+sqrt(5))^(n-1)-(2-sqrt(5))^(n-1))+(C(2*n,n) mod 2). - Paolo P. Lava (paoloplava(AT)gmail.com), Jan 26 2009
a(n) = Sum_{k, 0<=k<=n} A155161(n,k)*3^k. - DELEHAM Philippe, Feb 08 2012
|
|
|
MATHEMATICA
| Clear[f, lst, n, a] f[n_]:=Fibonacci[n]; lst={}; Do[a=f[n]*(3/2); If[IntegerQ[a], AppendTo[lst, a]], {n, 0, 5!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 25 2009]
|
|
|
CROSSREFS
| Sequence in context: A043291 A135343 A083314 * A104268 A081704 A166482
Adjacent sequences: A155176 A155177 A155178 * A155180 A155181 A155182
|
|
|
KEYWORD
| nonn,easy,changed
|
|
|
AUTHOR
| Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 21 2009
|
|
|
EXTENSIONS
| Entries corrected by Paolo P. Lava (paoloplava(AT)gmail.com), Jan 26 2009
|
| |
|
|
