|
|
A107068
|
|
Expansion of 1/((1+x)^3-x^4).
|
|
0
|
|
|
1, -3, 6, -10, 16, -27, 49, -92, 172, -316, 573, -1035, 1874, -3406, 6204, -11303, 20577, -37432, 68072, -123800, 225193, -409683, 745342, -1355970, 2466760, -4487395, 8163217, -14850196, 27015092, -49145300, 89404037, -162641499, 295872778, -538243174, 979156724, -1781254927, 3240410561
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
G.f.: 1/(1+3x+3x^2+x^3-x^4); a(n)=sum{k=0..n+4, (-1)^(n-k)*C(n+4, k)*sum{j=0..floor(k/4), C(k-3j, j)}}.
|
|
MATHEMATICA
|
LinearRecurrence[{-3, -3, -1, 1}, {1, -3, 6, -10}, 40] (* Harvey P. Dale, Jul 16 2018 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,sign
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|