A045948 - OEIS

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A045948

a(n) = A003418(n)/A034386(n).

1, 1, 1, 2, 2, 2, 2, 4, 12, 12, 12, 12, 12, 12, 12, 24, 24, 24, 24, 24, 24, 24, 24, 24, 120, 120, 360, 360, 360, 360, 360, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 5040, 5040, 5040, 5040, 5040, 5040, 5040, 5040, 5040

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Index entries for sequences related to lcm's

EXAMPLE

n=11: lcm(1..11) = 27720 = 8*9*5*7*11 = 2310*12. A034386(11)=2310, so the quotient is 12. Thus a(11) = 12.

MATHEMATICA

Table[Exp[Sum[MangoldtLambda[n], {n, 1, m}]]/ Product[x, {x, Prime[Range[PrimePi[m]]]}], {m, 1, 57}] (* Fred Daniel Kline, Apr 02 2015 *)

PROG

(PARI) a(n)=lcm([1..n])/prod(i=1, primepi(n), prime(i)) \\ Charles R Greathouse IV, Apr 02 2015; corrected by Michel Marcus, Dec 26 2020