|
|
A348289
|
|
a(n) = Sum_{k=0..floor(n/8)} binomial(n-4*k,4*k).
|
|
4
|
|
|
1, 1, 1, 1, 1, 1, 1, 1, 2, 6, 16, 36, 71, 127, 211, 331, 497, 725, 1047, 1531, 2316, 3668, 6064, 10312, 17717, 30309, 51165, 84893, 138417, 222329, 353285, 558253, 881918, 1399274, 2236480, 3604588, 5853067, 9553715, 15631615, 25570103, 41734433, 67889133, 110035211, 177778263
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,9
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (1-x)^3/((1-x)^4 - x^8).
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-8).
|
|
PROG
|
(PARI) a(n) = sum(k=0, n\8, binomial(n-4*k, 4*k));
(PARI) my(N=66, x='x+O('x^N)); Vec((1-x)^3/((1-x)^4-x^8))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|