A362988 - OEIS

%I #6 May 14 2023 09:39:18

%S 1,1,2,3,2,10,2,14,4,12,12,132,12,156,12,12,24,408,24,456,24,24,24,

%T 552,24,120,120,360,360,10440,360,11160,720,720,720,720,720,26640,720,

%U 720,720,29520,720,30960,720,720,720,33840,720,5040,5040,5040,5040,267120

%N a(n) = lcm({i, i = 1..n}) / Product_{2 <= p < n, p prime} p.

%e a(8)  = 2^2;

%e a(9)  = 2^2 * 3;

%e a(10) = 2^2 * 3;

%e a(11) = 2^2 * 3 * 11;

%e a(12) = 2^2 * 3;

%e a(13) = 2^2 * 3 * 13;

%p A362988 := n -> ilcm(seq(i, i = 1..n)) / mul(k, k = select(isprime, [$2..n-1])):

%p seq(A362988(n), n = 0..53);

%Y Cf. A003418 (lcm), A034386 (primorial).

%K nonn

%O 0,3

%A _Peter Luschny_, May 14 2023