|
1, -1, -1, -2, -5, -3, -11, -4, -19, -5, -29, -6, -41, -7, -55, -8, -71, -9, -89, -10, -109, -11, -131, -12, -155, -13, -181, -14, -209, -15, -239, -16, -271, -17, -305, -18, -341, -19, -379, -20, -419, -21, -461, -22, -505, -23, -551, -24, -599, -25, -649
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,4
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (1-x-4x^2+x^3+x^4)/((1-x)^3*(1+x)^3).
a(n) = 3a(n-2)-3a(n-4)+a(n-6).
a(n) = (6-n^2)(-1)^n/8-(n^2+4n-2)/8.
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,sign,changed
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|