|
|
A131292
|
|
a(2n+1)=3a(2n)-3a(2n-1)+2a(2n-2), a(2n+2)=3a(2n+1)-3a(2n), a(0)=a(1)=a(2)=1.
|
|
3
|
|
|
1, 1, 1, 2, 3, 5, 6, 9, 9, 12, 9, 9, 0, -9, -27, -54, -81, -135, -162, -243, -243, -324, -243, -243, 0, 243, 729, 1458, 2187, 3645, 4374, 6561, 6561, 8748, 6561, 6561, 0, -6561, -19683, -39366, -59049, -98415, -118098, -177147, -177147, -236196, -177147, -177147, 0, 177147, 531441, 1062882, 1594323
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,4
|
|
COMMENTS
|
Sequence is identical to its third differences in absolute value.
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (2*x^3-x^2-x+1)*(1+x)^2/(1-3*x^2+3*x^4). - R. J. Mathar, Jul 17 2009
|
|
MAPLE
|
|
|
MATHEMATICA
|
Join[{1, 1}, LinearRecurrence[{0, 3, 0, -3}, {1, 2, 3, 5}, 51]] (* Ray Chandler, Sep 23 2015 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|