|
|
A164551
|
|
a(n) = 10*a(n-1)-19*a(n-2) for n > 1; a(0) = 1, a(1) = 9.
|
|
3
|
|
|
1, 9, 71, 539, 4041, 30169, 224911, 1675899, 12485681, 93014729, 692919351, 5161913659, 38453668921, 286460329689, 2133983587391, 15897089609819, 118425207937761, 882207376791049, 6571994817093031, 48958008011900379
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
a(n) = ((3+2*sqrt(6))*(5+sqrt(6))^n+(3-2*sqrt(6))*(5-sqrt(6))^n)/6.
G.f.: (1-x)/(1-10*x+19*x^2).
|
|
MATHEMATICA
|
LinearRecurrence[{10, -19}, {1, 9}, 30] (* Harvey P. Dale, Dec 26 2015 *)
|
|
PROG
|
(Magma) [ n le 2 select 8*n-7 else 10*Self(n-1)-19*Self(n-2): n in [1..20] ];
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|