|
Search: id:A052562
|
|
|
| A052562 |
|
Quintuple factorial numbers: a(n) = 5^n*n!. |
|
+0
19
|
|
| 1, 5, 50, 750, 15000, 375000, 11250000, 393750000, 15750000000, 708750000000, 35437500000000, 1949062500000000, 116943750000000000, 7601343750000000000, 532094062500000000000, 39907054687500000000000
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
A simple regular expression in a labeled universe.
For n >= 1 a(n) is the order of the wreath product of the symmetric group S_n and the Abelian group (C_5)^n. - Ahmed Fares (ahmedfares(AT)my-deja.com), May 07 2001
|
|
REFERENCES
|
Michael Z. Spivey and Laura L. Steil, The k-Binomial Transforms and the Hankel Transform, Journal of Integer Sequences, Vol. 9 (2006), Article 06.1.1.
|
|
LINKS
|
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 504
|
|
FORMULA
|
E.g.f.: 1/(1-5*x).
Recurrence: {a(0)=1, (-5*n-5)*a(n)+a(n+1)}
|
|
MAPLE
|
spec := [S, {S=Sequence(Union(Z, Z, Z, Z, Z))}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
with(combstruct):A:=[N, {N=Cycle(Union(Z$5))}, labeled]: seq(count(A, size=n)/5, n=1..16); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 05 2007
|
|
MATHEMATICA
|
s=1; lst={s}; Do[s+=n*s; AppendTo[lst, s], {n, 4, 5!, 5}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 08 2008]
|
|
CROSSREFS
|
Cf. A000142, A008548, A008546, A034325, A000165. a(n)= A051150(n+1, 0) (first column of triangle).
Sequence in context: A093146 A049393 A047054 this_sequence A113132 A088992 A116906
Adjacent sequences: A052559 A052560 A052561 this_sequence A052563 A052564 A052565
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
Joe Keane (jgk(AT)jgk.org)
|
|
|
Search completed in 0.002 seconds
|
