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%I #14 Sep 08 2022 08:44:39
%S 1,-7,-399,181545,661005345,-19253102683815,-4486300228074519855,
%T 8363069275661695069900425,124719129516554187174725699959425,
%U -14879571721119777957252576955487113947975
%N q-factorial numbers for q=-8.
%H Vincenzo Librandi, <a href="/A015022/b015022.txt">Table of n, a(n) for n = 1..40</a>
%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>
%F Prod_{k=1}^{n} (q^k - 1) / (q - 1).
%F a(1) = 1, a(n) = ((-8)^n - 1)*a(n-1)/(-9). - _Vincenzo Librandi_, Oct 26 2012
%t RecurrenceTable[{a[1]==1, a[n]==(((-8)^n - 1) * a[n-1])/(-9)}, a, {n, 15}] (* _Vincenzo Librandi_, Oct 26 2012 *)
%o (Magma) [n le 1 select 1 else ((-8)^n - 1)*Self(n-1)/(-9): n in [1..13]]; // _Vincenzo Librandi_, Oct 26 2012
%K sign,easy
%O 1,2
%A _Olivier Gérard_