%I #14 Sep 08 2022 08:44:39
%S 1,-12,-1884,3843360,101929750560,-35142523960072320,
%T -157510092662430660915840,9177558663913662855639573043200,
%U 6951672507594336724476921764731548211200
%N q-factorial numbers for q=-13.
%H Vincenzo Librandi, <a href="/A015028/b015028.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) = ((-13)^n - 1)*a(n-1)/(-14). - _Vincenzo Librandi_, Oct 26 2012
%t RecurrenceTable[{a[1]==1, a[n]==(((-13)^n - 1) a[n-1])/(-14)}, a, {n, 15}] (* _Vincenzo Librandi_, Oct 26 2012 *)
%o (Magma) [n le 1 select 1 else ((-13)^n - 1)*Self(n-1)/(-14): n in [1..13]]; // _Vincenzo Librandi_, Oct 26 2012
%K sign,easy
%O 1,2
%A _Olivier GĂ©rard_