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

%I #28 Feb 26 2024 01:59:07

%S 1,1,2,3,8,15,144,35,1152,2835,6400,6237,6220800,1001,609638400,

%T 13030875,1605632,221524875,21069103104,5773625,52672757760000,

%U 311834363841,39649280000,652017306213,18730002677760000

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

%H Charlie Neder, <a href="/A129108/b129108.txt">Table of n, a(n) for n = 0..619</a>

%F 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

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

%K nonn

%O 0,3

%A _Leroy Quet_, May 24 2007

%E More terms from _R. J. Mathar_, Jun 15 2007

%E a(14)-a(24) corrected by _Charlie Neder_, Jan 06 2019