A384453 a(n) is the n-th q-factorial number for q=-n.

1, 1, -1, -14, 1989, 4551456, -212333070125, -246183190158589200, 8363069275661695069900425, 9589835030046843645163231485460480, -420238291486760860506028808179511473194550689, -785971734280677729025139143429963192709390305509012000000

Offset

0,4

Links

Table of n, a(n) for n=0..11.

Index entries for sequences related to factorial numbers.

Formula

a(n) = Product_{k=1..n} (1 - (-n)^k)/(1 + n).

Mathematica

Table[QFactorial[n, -n], {n, 0, 11}] (* Amiram Eldar, Aug 10 2025 *)

Prog

(PARI) a(n) = prod(k=1, n, (1-(-n)^k)/(1+n));

Crossrefs

Main diagonal of A384454.

Cf. A347611.

Sequence in context: A279804 A198601 A233076 * A134814 A258487 A206753

Adjacent sequences: A384450 A384451 A384452 * A384454 A384455 A384456

Keyword

sign

Author

Seiichi Manyama, May 30 2025

Status

approved