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A129108

a(0)=1; a(n) is the smallest positive integer such that lcm(a(n-1), a(n)) = n!.

1, 1, 2, 3, 8, 15, 144, 35, 1152, 2835, 6400, 6237, 6220800, 1001, 609638400, 13030875, 1605632, 221524875, 21069103104, 5773625, 52672757760000, 311834363841, 39649280000, 652017306213, 18730002677760000

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OFFSET

0,3

LINKS

Charlie Neder, Table of n, a(n) for n = 0..619

FORMULA

If n! = Product p_i^e_i, then a(n) = Product{p_i^e_i : n has even remainder mod p_i}. - Charlie Neder, Jan 06 2019

EXAMPLE

lcm(a(5), a(6)) = lcm(15, 144) = 720 = 6!.

MATHEMATICA

s={1}; Do[k=0; Until[LCM[s[[-1]], k]==n!, k++]; AppendTo[s, k], {n, 13}]; s (* James C. McMahon, Jan 15 2025 *)

CROSSREFS

Sequence in context: A005162 A350654 A387027 * A230284 A264235 A160622

Adjacent sequences: A129105 A129106 A129107 * A129109 A129110 A129111

KEYWORD

nonn

AUTHOR

Leroy Quet, May 24 2007

EXTENSIONS

More terms from R. J. Mathar, Jun 15 2007

a(14)-a(24) corrected by Charlie Neder, Jan 06 2019

STATUS

approved

URL: https://oeis.org/A129108

⇱ A129108 - OEIS