A203466 a(n) = A203306(n)/A000178(n) where A000178 are superfactorials.

1, 1, 10, 15180, 97199847360, 124679879327832253286400, 2359315315713931476611812172370616909824000, 69427548091550819116702789435220590352184299509517898727953530880000000

Offset

1,3

Links

G. C. Greubel, Table of n, a(n) for n = 1..16

R. Chapman, A polynomial taking integer values, Mathematics Magazine, 29 (1996), 121.

Mathematica

f[j_]:= j!; z = 10;
v[n_]:= Product[Product[f[k] - f[j], {j, k-1}], {k, 2, n}]
d[n_]:= Product[(i-1)!, {i, n}]
Table[v[n], {n, z}]       (* A203306 *)
Table[v[n]/d[n], {n, z}]  (* A203466 *)

Prog

(Magma) F:= Factorial; [1] cat [(&*[(&*[F(k+1) - F(j): j in [1..k]])/Factorial(k): k in [1..n-1]]): n in [2..20]]; // G. C. Greubel, Sep 19 2023
(SageMath) f=factorial; [product(product(f(k+1) - f(j) for j in range(1, k+1))//factorial(k) for k in range(1, n)) for n in range(1, 21)] # G. C. Greubel, Sep 19 2023

Crossrefs

Cf. A203306.

Sequence in context: A190946 A052498 A179425 * A203695 A181017 A360213

Adjacent sequences: A203463 A203464 A203465 * A203467 A203468 A203469

Keyword

nonn

Author

Clark Kimberling, Jan 02 2012

Extensions

Name edited by Michel Marcus, May 17 2019

Status

approved