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%I #17 Mar 18 2018 04:06:35
%S 1,1,1,1,2,1,1,3,3,1,1,4,6,2,1,1,5,10,10,5,1,1,6,15,10,5,1,1,1,7,21,
%T 35,35,7,7,1,1,8,28,28,70,14,14,2,1,1,9,36,84,42,42,42,6,3,1,1,10,45,
%U 60,210,42,42,6,3,1,1,1,11,55,165,330,462,462,66,33,11,11,1,1,12,66,110
%N Triangle T(n,r) = lcm(n,n-1,n-2,...,n-r+1)/lcm(1,2,3,...,r-1,r), 0 <= r < n.
%D Amarnath Murthy, Some Notions on Least Common Multiples, Smarandache Notions Journal, Vol. 12, No. 1-2-3, Spring 2001.
%e Triangle begins:
%e 1;
%e 1, 1;
%e 1, 2, 1;
%e 1, 3, 3, 1;
%e 1, 4, 6, 2, 1; ...
%t t[n_, r_] := LCM @@ Table[n-k+1, {k, 1, r}] / LCM @@ Table[k, {k, 1, r}]; t[_, 0] = 1; Table[t[n, r], {n, 0, 12}, {r, 0, n}] // Flatten (* _Jean-François Alcover_, Apr 22 2014 *)
%o (PARI) t(n, r) = {nt = 1; for (k = n-r+1, n, nt = lcm(nt, k);); dt = 1; for (k = 1, r, dt = lcm(dt, k);); return (nt/dt);} \\ _Michel Marcus_, Sep 14 2013
%Y Diagonals give A067046, A067047, A067048. Row sums give A061297.
%K nonn,tabl
%O 0,5
%A _Amarnath Murthy_, Dec 30 2001
%E More terms from _Vladeta Jovovic_, Dec 31 2001
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