|
| |
|
|
A052917
|
|
Expansion of 1/(1-3x-x^4).
|
|
1
| |
|
|
1, 3, 9, 27, 82, 249, 756, 2295, 6967, 21150, 64206, 194913, 591706, 1796268, 5453010, 16553943, 50253535, 152556873, 463123629, 1405924830, 4268028025, 12956640948, 39333046473, 119405064249, 362483220772, 1100406303264
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 900
Index to sequences with linear recurrences with constant coefficients, signature (3,0,0,1)
|
|
|
FORMULA
| G.f.: -1/(-1+3*x+x^4)
Recurrence: {a(0)=1, a(1)=3, a(2)=9, a(n)+3*a(n+3)-a(n+4), a(3)=27}
Sum(1/2443*(729+324*_alpha^3+144*_alpha^2+64*_alpha)*_alpha^(-1-n), _alpha=RootOf(-1+3*_Z+_Z^4))
|
|
|
MAPLE
| spec := [S, {S=Sequence(Union(Z, Z, Z, Prod(Z, Z, Z, Z)))}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);
|
|
|
CROSSREFS
| Sequence in context: A067500 A078226 A083591 * A099786 A192909 A171155
Adjacent sequences: A052914 A052915 A052916 * A052918 A052919 A052920
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
|
|
|
EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 06 2000
|
| |
|
|
