|
Search: id:A052914
|
|
|
| A052914 |
|
A simple regular expression. |
|
+0
1
|
|
| 1, 0, 0, 1, 3, 1, 2, 7, 12, 10, 19, 41, 61, 76, 135, 240, 356, 521, 879, 1445, 2198, 3407, 5568, 8898, 13811, 21797, 35017, 55488, 87111, 138100, 220028, 348081, 549427, 871433, 1383370, 2188903, 3463028, 5490410, 8703187, 13777281, 21815941
(list; graph; listen)
|
|
|
OFFSET
|
0,5
|
|
|
LINKS
|
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 896
|
|
FORMULA
|
G.f.: -(-1+x)/(1-x-2*x^4+2*x^5-x^3)
Recurrence: {a(1)=0, a(0)=1, a(2)=0, a(3)=1, a(4)=3, 2*a(n)-2*a(n+1)-a(n+2)-a(n+4)+a(n+5)}
Sum(-1/19913*(-418-4709*_alpha+599*_alpha^2+1048*_alpha^3+542*_alpha^4)*_alpha^(-1-n), _alpha=RootOf(1-_Z-2*_Z^4+2*_Z^5-_Z^3))
|
|
MAPLE
|
spec := [S, {S=Sequence(Prod(Union(Sequence(Z), Z, Z), Z, Z, Z))}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);
|
|
CROSSREFS
|
Sequence in context: A135338 A084602 A100888 this_sequence A131671 A060750 A086961
Adjacent sequences: A052911 A052912 A052913 this_sequence A052915 A052916 A052917
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
|
|
EXTENSIONS
|
More terms from James A. Sellers (sellersj(AT)math.psu.edu), May 06 2000
|
|
|
Search completed in 0.002 seconds
|
