login
q-factorial numbers for q=-12.
1

%I #14 Sep 08 2022 08:44:39

%S 1,-11,-1463,2333485,44665236385,-10259202810507035,

%T -28277368892180867021255,935288538953861649874525071325,

%U 371221802129246962654056875248358359825,-1768082733073463162105209099485375242162416580075

%N q-factorial numbers for q=-12.

%H Vincenzo Librandi, <a href="/A015027/b015027.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) = ((-12)^n -1)*a(n-1)/(-13). - _Vincenzo Librandi_, Oct 26 2012

%t RecurrenceTable[{a[1]==1, a[n]==(((-12)^n - 1) * a[n-1])/(-13)}, a, {n, 15}] (* _Vincenzo Librandi_, Oct 26 2012 *)

%o (Magma) [n le 1 select 1 else ((-12)^n - 1)*Self(n-1)/(-13): n in [1..13]]; // _Vincenzo Librandi_, Oct 26 2012

%K sign,easy

%O 1,2

%A _Olivier GĂ©rard_