|
Search: id:A034301
|
|
|
| A034301 |
|
One quarter of quintic factorial numbers. |
|
+0
14
|
|
| 1, 9, 126, 2394, 57456, 1666224, 56651616, 2209413024, 97214173056, 4763494479744, 257228701906176, 15176493412464384, 971295578397720576, 67019394909442719744, 4959435223298761261056, 391795382640602139623424
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
FORMULA
|
4*a(n) = (5*n-1)(!^5) := product(5*j-1, j=1..n) = (5*n)!/(5^n*n!*A008548(n)*2*A034323(n)*3*A034300(n)); E.g.f. (-1+(1-5*x)^(-4/5))/4, a(0) := 0.
a(n) ~ 5/4*2^(1/2)*pi^(1/2)*Gamma(4/5)^-1*n^(13/10)*5^n*e^-n*n^n*{1 + 241/300*n^-1 + ...}. - Joe Keane (jgk(AT)jgk.org), Nov 24 2001
|
|
MATHEMATICA
|
s=1; lst={s}; Do[s+=n*s; AppendTo[lst, s], {n, 8, 5!, 5}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 08 2008]
|
|
CROSSREFS
|
Cf. A008548, A034300, A025750.
Sequence in context: A144073 A065086 A065707 this_sequence A092651 A073014 A046754
Adjacent sequences: A034298 A034299 A034300 this_sequence A034302 A034303 A034304
|
|
KEYWORD
|
easy,nonn,new
|
|
AUTHOR
|
Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)
|
|
|
Search completed in 0.002 seconds
|
