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A015007 q-factorial numbers for q=8. 2
1, 9, 657, 384345, 1799118945, 67375205371305, 20185139902805378865, 48378633136349277767794425, 927610024989668734297857360967425, 142287668466497494704440569679875994730825 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..40

Index entries for sequences related to factorial numbers

FORMULA

Prod_{k=1}^{n} ((q^k - 1) / (q - 1)).

a(1) = 1, a(n) = (8^n-1)*a(n-1)/7. - Vincenzo Librandi, Oct 26 2012

MATHEMATICA

RecurrenceTable[{a[1]==1, a[n]==((8^n - 1) * a[n-1])/7}, a, {n, 15}] (* Vincenzo Librandi, Oct 26 2012 *)

Table[QFactorial[n, 8], {n, 15}] (* Bruno Berselli, Aug 14 2013 *)

PROG

(MAGMA) [n le 1 select 1 else (8^n-1)*Self(n-1)/7: n in [1..15]]; // Vincenzo Librandi, Oct 26 2012

CROSSREFS

Sequence in context: A020548 A091062 A221133 * A054327 A209964 A287937

Adjacent sequences:  A015004 A015005 A015006 * A015008 A015009 A015010

KEYWORD

nonn,easy

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified October 16 15:48 EDT 2019. Contains 328101 sequences. (Running on oeis4.)