A015028 q-factorial numbers for q=-13.

1, -12, -1884, 3843360, 101929750560, -35142523960072320, -157510092662430660915840, 9177558663913662855639573043200, 6951672507594336724476921764731548211200

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) = ((-13)^n - 1)*a(n-1)/(-14). - Vincenzo Librandi, Oct 26 2012

Mathematica

RecurrenceTable[{a[1]==1, a[n]==(((-13)^n - 1) a[n-1])/(-14)}, a, {n, 15}] (* Vincenzo Librandi, Oct 26 2012 *)

Prog

(Magma) [n le 1 select 1 else ((-13)^n - 1)*Self(n-1)/(-14): n in [1..13]]; // Vincenzo Librandi, Oct 26 2012

Crossrefs

Sequence in context: A229752 A104009 A261946 * A167745 A326601 A265216

Adjacent sequences: A015025 A015026 A015027 * A015029 A015030 A015031

Keyword

sign,easy

Author

Olivier Gérard

Status

approved