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A263884 a(n) = (m(n)*n)! / (n!)^(m(n)+1), where m(n) is the largest prime power <= n. 0
1, 3, 280, 2627625, 5194672859376, 1903991899429620, 1461034854396267778567973305958400, 450538787986875167583433232345723106006796340625, 146413934927214422927834111686633731590253260933067148964500000000, 3752368324673960479843764075706478869144868251518618794695144146928706880 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Morris and Fritze (2015) prove that a(n) is an integer.

LINKS

Table of n, a(n) for n=1..10.

Howard Carry Morris and Daniel Fritze, Problem 1948, Math. Mag., 88 (2015), 288-289.

FORMULA

a(n) = A057599(n) for n a prime power.

EXAMPLE

The largest prime power <= 6 is m(6) = 5, so a(6) = (5*6)! / (6!)^(5+1) = 30! / (6!)^6 = 1903991899429620.

CROSSREFS

Cf. A057599.

Sequence in context: A051365 A003706 A068250 * A096126 A057599 A239273

Adjacent sequences:  A263881 A263882 A263883 * A263885 A263886 A263887

KEYWORD

nonn

AUTHOR

Jonathan Sondow, Dec 19 2015

STATUS

approved

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Last modified August 11 06:25 EDT 2020. Contains 336422 sequences. (Running on oeis4.)