|
| |
|
|
A052903
|
|
Expansion of (1-x^3)/(1-2x-x^3+x^4).
|
|
0
| |
|
|
1, 2, 4, 8, 17, 36, 76, 161, 341, 722, 1529, 3238, 6857, 14521, 30751, 65121, 137906, 292042, 618454, 1309693, 2773522, 5873456, 12438151, 26340131, 55780196, 118125087, 250152154, 529744373, 1121833637, 2375694341, 5030980901
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Partial sums of A052908. - R. J. Mathar, Nov 28 2011
|
|
|
LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 881
Index to sequences with linear recurrences with constant coefficients, signature (2,0,1,-1)
|
|
|
FORMULA
| G.f.: -(-1+x^3)/(1-2*x-x^3+x^4)
Recurrence: {a(0)=1, a(2)=4, a(1)=2, a(3)=8, a(n)-a(n+1)-2*a(n+3)+a(n+4)=0}
Sum(-1/643*(-222-40*_alpha-93*_alpha^2+54*_alpha^3)*_alpha^(-1-n), _alpha=RootOf(1-2*_Z-_Z^3+_Z^4))
|
|
|
MAPLE
| spec := [S, {S=Sequence(Union(Z, Prod(Sequence(Prod(Z, Z, Z)), Z)))}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);
|
|
|
CROSSREFS
| Sequence in context: A182900 A202843 A008999 * A063457 A190162 A157904
Adjacent sequences: A052900 A052901 A052902 * A052904 A052905 A052906
|
|
|
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 05 2000
|
| |
|
|
