

A053023


Divisor function applied thrice to n!.


0



1, 2, 2, 3, 2, 4, 6, 6, 6, 5, 8, 8, 8, 8, 8, 9, 8, 10, 8, 10, 10, 12, 10, 10, 10, 15, 16, 16, 18, 16, 8, 16, 10, 12, 16, 18, 14, 3, 14, 16, 24, 16, 16, 20, 24, 24, 28, 24, 24, 16, 24, 24, 32, 32, 28, 32, 18, 20, 24, 28, 36, 32, 36, 24, 21, 24, 20, 40, 40, 30, 30, 36, 40, 42, 24, 32
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..76.


FORMULA

d[ d[ d[ n! ] ] ] = A036450(A000142(n)) = A036450(n!)


EXAMPLE

A036450[x]=8 if x = 11!, 12!, 13!, 14!, 15!. The reversed sequences of these diterates are {2, 3, 4, 8, 24, 540, 39916800}, {2, 3, 4, 8, 24, 792, 479001600}, {2, 3, 4, 8, 30, 1584, 6227020800}, {2, 3, 4, 8, 30, 2592, 87178291200}, {2, 3, 4, 8, 42, 4032, 1307674368000}.


CROSSREFS

Cf. A000005, A027473, A010553, A036450, A000142.
Sequence in context: A239471 A241509 A268327 * A153725 A102247 A054249
Adjacent sequences: A053020 A053021 A053022 * A053024 A053025 A053026


KEYWORD

nonn


AUTHOR

Labos Elemer, Feb 24 2000


STATUS

approved



