%I #15 Oct 06 2016 10:34:18

%S 1,1,2,6,12,60,60,420,840,2520,2520,27720,13860,180180,360360,360360,

%T 720720,12252240,4084080,77597520,38798760,116396280,232792560,

%U 5354228880,1338557220,6692786100,13385572200,40156716600,80313433200

%N a(n) = n!*(floor(n/30))!/((floor(n/2))!*(floor(n/3))!*(floor(n/5))!).

%C For positive real r the ratio of factorials floor((30*r*n))! * (floor(r*n))!/((floor(15*r*n))!*(floor(10*r*n))!*(floor(6*r*n))!) is an integer. The present sequence is the case r = 1/30. The case r = 1 is A211417.

%H Carauleanu Marc, <a href="/A211418/b211418.txt">Table of n, a(n) for n = 0..424</a>

%H P. Bala, <a href="/A211417/a211417_1.txt">Proof of the integrality of A211417 and A211418 </a>

%o (PARI) a(n) = n!*(floor(n/30))!/((floor(n/2))!*(floor(n/3))!*(floor(n/5))!);

%o vector(50, n, a(n-1)) \\ _Altug Alkan_, Oct 02 2015

%Y Cf. A211417.

%K nonn,easy

%O 0,3

%A _Peter Bala_, Apr 11 2012