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A242456
Least number k such that n!/k is prime.
2
1, 2, 8, 24, 144, 720, 5760, 51840, 518400, 3628800, 43545600, 479001600, 6706022400, 100590336000, 1609445376000, 20922789888000, 376610217984000, 6402373705728000, 128047474114560000, 2688996956405760000, 59157933040926720000, 1124000727777607680000, 26976017466662584320000, 674400436666564608000000
OFFSET
2,2
LINKS
FORMULA
a(n) = n!/prime(pi(n)) = A000142(n)/A007917(n) for n > 1.
MAPLE
with(numtheory): A242456:=n->n!/ithprime(pi(n)): seq(A242456(n), n=2..30); # Wesley Ivan Hurt, Aug 17 2014
MATHEMATICA
Table[n!/Prime[PrimePi[n]], {n, 2, 30}] (* Wesley Ivan Hurt, Aug 17 2014 *)
PROG
(PARI)
vector(50, n, (n+1)!/(prime(primepi(n+1))))
CROSSREFS
Sequence in context: A176475 A145238 A093458 * A353779 A088994 A330505
KEYWORD
nonn,easy
AUTHOR
Derek Orr, Aug 16 2014
STATUS
approved