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A034911 One fifth of octo-factorial numbers. 3
1, 13, 273, 7917, 292929, 13181805, 698635665, 42616775565, 2940557513985, 226422928576845, 19245948929031825, 1789873250399959725, 180777198290395932225, 19704714613653156612525 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..14.

Index entries for sequences related to factorial numbers

FORMULA

5*a(n) = (8*n-3)(!^8) = product(8*j-3, j=1..n).

E.g.f.: (-1+(1-8*x)^(-5/8))/5.

G.f.: x/(1-13x/(1-8x/(1-21x/(1-16x/(1-29x/(1-24x/(1-37x/(1-32x/(1-... (continued fraction). - Philippe Deléham, Jan 07 2012

MATHEMATICA

s=1; lst={s}; Do[s+=n*s; AppendTo[lst, s], {n, 12, 5!, 8}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 08 2008 *)

With[{nn=20}, CoefficientList[Series[(-1+(1-8x)^(-5/8))/5, {x, 0, nn}], x] Range[0, nn]!] (* or *) FoldList[Times, Range[5, 200, 8]]/5 (* Harvey P. Dale, May 25 2016 *)

CROSSREFS

Cf. A045755, A034908-A034912.

Sequence in context: A163155 A183515 A001658 * A196652 A197455 A196342

Adjacent sequences:  A034908 A034909 A034910 * A034912 A034913 A034914

KEYWORD

easy,nonn

AUTHOR

Wolfdieter Lang

STATUS

approved

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Last modified November 14 09:49 EST 2018. Contains 317182 sequences. (Running on oeis4.)