OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..35
FORMULA
a(n) = n! * A002109(n). - Vaclav Kotesovec, Jan 26 2016
a(n) = (n!)^2 * abs(A203421(n)). - Michel Marcus, Feb 11 2016
MAPLE
a:= proc(n) a(n):= `if`(n=0, 1, a(n-1)*n^(n+1)) end:
seq(a(n), n=0..12); # Alois P. Heinz, Feb 10 2016
MATHEMATICA
a[n_]:= Product[k^(k+1), {k, n}]; Table[a[n], {n, 0, 20}]
Table[Hyperfactorial[n]*n!, {n, 0, 15}] (* Vaclav Kotesovec, Jan 26 2016 *)
PROG
(Magma) [&*[k^(k+1): k in [1..n]]: n in [1..11]]; // Vincenzo Librandi, Jan 23 2016
(PARI) a(n) = prod(k=1, n, k^(k+1)); \\ Michel Marcus, Jan 23 2016
(SageMath) [product(k^(k+1) for k in range(1, n+1)) for n in range(21)] # G. C. Greubel, Feb 18 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
José María Grau Ribas, Jan 22 2016
STATUS
approved