login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A034908 One half of octo-factorial numbers. 11
1, 10, 180, 4680, 159120, 6683040, 334152000, 19380816000, 1279133856000, 94655905344000, 7761784238208000, 698560581438720000, 68458936980994560000, 7256647319985423360000, 827257794478338263040000, 100925450926357268090880000, 13120308620426444851814400000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..333

Index entries for sequences related to factorial numbers

FORMULA

2*a(n) = (8*n-6)(!^8) := product(8*j-6, j=1..n) = 2^n*A007696(n), A007696(n)=(4*n-3)(!^4) := product(4*j-3, j=1..n).

E.g.f.: (-1+(1-8*x)^(-1/4))/2.

G.f.: x/(1-10x/(1-8x/(1-18x/(1-16x/(1-26x/(1-24x/(1-34x/(1-32x/(1-... (continued fraction). - Philippe Deléham, Jan 07 2012

MATHEMATICA

Drop[With[{nn = 40}, CoefficientList[Series[(-1 + (1 - 8*x)^(-1/4))/2, {x, 0, nn}], x]*Range[0, nn]!], 1] (* G. C. Greubel, Feb 26 2018 *)

PROG

(PARI) x='x+O('x^30); Vec(serlaplace((-1+(1-8*x)^(-1/4))/2)) \\ G. C. Greubel, Feb 26 2018

(MAGMA) [(&*[(8*k-6): k in [1..n]])/2: n in [1..30]]; // G. C. Greubel, Feb 26 2018

CROSSREFS

Cf. A045755, A034909, A039410, A039411, A039412.

Sequence in context: A067416 A113671 A001762 * A030048 A318796 A054918

Adjacent sequences:  A034905 A034906 A034907 * A034909 A034910 A034911

KEYWORD

easy,nonn

AUTHOR

Wolfdieter Lang

EXTENSIONS

Terms a(16) onward added by G. C. Greubel, Feb 26 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 19 20:41 EST 2020. Contains 331066 sequences. (Running on oeis4.)