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A240098 Product of the greatest common divisors of n and k! over k=0..n-1. 2
1, 1, 1, 4, 1, 432, 1, 16384, 19683, 800000, 1, 5159780352, 1, 3373232128, 5189853515625, 281474976710656, 1, 499751156776108032, 1, 52428800000000000000, 262757514534242203161, 299170970322599936, 1, 48239864614087244084529856512, 2910383045673370361328125 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..25.

FORMULA

a(n) = product_{k=0..n-1} gcd(n,k!) = n^n/A058067(n).

a(p) = 1 for primes p. - Joerg Arndt, Apr 01 2014

a(p^2)= p^(p*(2*p-3)) for primes p. - R. J. Mathar, Apr 02 2014

MAPLE

A240098 := proc(n)

    mul( igcd(n, k!), k=0..n-1) ;

end proc:

MATHEMATICA

Table[Times@@Table[GCD[i, n!], {n, 0, i-1}], {i, 30}] (* Harvey P. Dale, Feb 23 2015 *)

CROSSREFS

Sequence in context: A299522 A300140 A298939 * A094337 A038019 A164804

Adjacent sequences:  A240095 A240096 A240097 * A240099 A240100 A240101

KEYWORD

nonn,easy

AUTHOR

R. J. Mathar, Apr 01 2014

EXTENSIONS

More terms from Harvey P. Dale, Feb 23 2015

STATUS

approved

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Last modified September 15 22:10 EDT 2019. Contains 327088 sequences. (Running on oeis4.)