|
Search: id:A052695
|
|
|
| A052695 |
|
A simple regular expression in a labeled universe. |
|
+0
1
|
|
| 2, 5, 34, 390, 6168, 123000, 2949840, 82580400, 2642451840, 95127177600, 3805076217600, 167423233824000, 8036313786547200, 417888298219392000, 23401744438751078400, 1404104662402041600000, 89862698330962292736000
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
LINKS
|
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 644
|
|
FORMULA
|
E.g.f.: -(-2+5*x)/(-1+4*x)/(-1+x)
Recurrence: {a(1)=5, a(0)=2, (4*n^2+12*n+8)*a(n)+(-10-5*n)*a(n+1)+a(n+2)}
(4^n+1)*n!
|
|
MAPLE
|
spec := [S, {S=Union(Sequence(Z), Sequence(Union(Z, Z, Z, Z)))}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
|
|
CROSSREFS
|
Sequence in context: A019038 A114793 A027303 this_sequence A002665 A000665 A058882
Adjacent sequences: A052692 A052693 A052694 this_sequence A052696 A052697 A052698
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
|
|
|
Search completed in 0.002 seconds
|
