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A153823 Number of proper divisors of n!. 2
0, 0, 1, 3, 7, 15, 29, 59, 95, 159, 269, 539, 791, 1583, 2591, 4031, 5375, 10751, 14687, 29375, 41039, 60799, 95999, 191999, 242879, 340031, 532223, 677375, 917279, 1834559, 2332799, 4665599, 5529599, 7864319, 12165119, 16422911 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

a(n) is the number of proper divisors of factorial number A000142(n).

FORMULA

a(n) = A000005(A000142(n))-1 = A032741(A000142(n)) = A027423(n)-1.

CROSSREFS

Cf. A000005, A000142, A027423, A032741.

Cf. A153823, A153825. [From Omar E. Pol (info(AT)polprimos.com), Jan 17 2009]

Sequence in context: A132780 A018087 A171625 * A080011 A120538 A146019

Adjacent sequences:  A153820 A153821 A153822 * A153824 A153825 A153826

KEYWORD

nonn

AUTHOR

Omar E. Pol (info(AT)polprimos.com), Jan 02 2009

EXTENSIONS

More terms from Omar E. Pol (info(AT)polprimos.com), Jan 17 2009

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Last modified February 13 20:06 EST 2012. Contains 205552 sequences.