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A308820 a(n) = Product_{k=1..n} ceiling(n/k)!. 0
1, 2, 12, 96, 2880, 34560, 5806080, 92897280, 25082265600, 2006581248000, 794606174208000, 19070548180992000, 208250386136432640000, 5831010811820113920000, 4198327784510482022400000, 3224315738504050193203200000, 14799609239733590386802688000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..17.

FORMULA

a(n) = Product_{k=1..n-1} Product_{d|k} (d + 1).

MATHEMATICA

a[n_] := Product[Ceiling[n/k]!, {k, 1, n}]; Table[a[n], {n, 1, 17}]

PROG

(PARI) a(n) = prod(k=1, n, ceil(n/k)!); \\ Michel Marcus, Jun 27 2019

CROSSREFS

Cf. A010786, A020696, A092143, A131385.

Sequence in context: A340938 A059864 A095338 * A322717 A219538 A245897

Adjacent sequences:  A308817 A308818 A308819 * A308821 A308822 A308823

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Jun 26 2019

STATUS

approved

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Last modified July 26 17:37 EDT 2021. Contains 346294 sequences. (Running on oeis4.)