A015026 q-factorial numbers for q=-11.

1, -10, -1110, 1354200, 18174718200, -2683133647866000, -4357223907912681246000, 77834136400782124140797040000, 15294068523753116384387488625702640000, -33057395763506647102922925284376653918412000000

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) = ((-11)^n - 1) * a(n-1)/(-12). - Vincenzo Librandi, Oct 26 2012

Mathematica

RecurrenceTable[{a[1]==1, a[n]==(((-11)^n - 1) a[n-1])/(-12)}, a, {n, 15}] (* Vincenzo Librandi, Oct 26 2012 *)

Prog

(Magma) [n le 1 select 1 else ((-11)^n - 1)*Self(n-1)/(-12): n in [1..13]]; // Vincenzo Librandi, Oct 26 2012

Crossrefs

Sequence in context: A267246 A355316 A266589 * A130598 A267595 A266621

Adjacent sequences: A015023 A015024 A015025 * A015027 A015028 A015029

Keyword

sign,easy

Author

Olivier Gérard

Status

approved