|
|
A289414
|
|
a(n) = ((10-sqrt(10))^n + (10+sqrt(10))^n) / 2.
|
|
4
|
|
|
1, 10, 110, 1300, 16100, 205000, 2651000, 34570000, 452810000, 5944900000, 78145100000, 1027861000000, 13524161000000, 177975730000000, 2342340110000000, 30828986500000000, 405769120100000000, 5340773617000000000, 70296251531000000000, 925255405090000000000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (1 - 10*x) / (1 - 20*x + 90*x^2).
a(n) = 20*a(n-1) - 90*a(n-2) for n>1.
|
|
MAPLE
|
a:= n-> (<<0|1>, <-90|20>>^n. <<1, 10>>)[1, 1]:
|
|
PROG
|
(PARI) Vec((1 - 10*x) / (1 - 20*x + 90*x^2) + O(x^25))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|