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A015001 q-factorial numbers for q=3. 3
1, 4, 52, 2080, 251680, 91611520, 100131391360, 328430963660800, 3232089113385932800, 95424198983606279987200, 8452007576574959037306265600, 2245867453247498115393020895232000, 1790317944898228845164815929864036352000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..50

Index entries for sequences related to factorial numbers

FORMULA

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

a(1) = 1, a(n) = (3^n - 1)*a(n-1)/2. - Vincenzo Librandi, Oct 27 2012

MATHEMATICA

RecurrenceTable[{a[1]==1, a[n]==((3^n - 1) * a[n-1])/2}, a, {n, 15}] (* Vincenzo Librandi, Oct 27 2012 *)

Table[QFactorial[n, 3], {n, 15}] (* Bruno Berselli, Aug 14 2013 *)

PROG

(MAGMA) [n le 1 select 1 else (3^n-1)*Self(n-1)/2: n in [1..15]]; // Vincenzo Librandi, Oct 22 2012

CROSSREFS

Sequence in context: A277353 A055974 A009671 * A317829 A327234 A327373

Adjacent sequences:  A014998 A014999 A015000 * A015002 A015003 A015004

KEYWORD

nonn,easy

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified February 23 07:11 EST 2020. Contains 332159 sequences. (Running on oeis4.)