A120435 Triangle read by rows: T(n,k) = lcm(1,2,3,4,...,n)/k (1 <= k <= n).

1, 2, 1, 6, 3, 2, 12, 6, 4, 3, 60, 30, 20, 15, 12, 60, 30, 20, 15, 12, 10, 420, 210, 140, 105, 84, 70, 60, 840, 420, 280, 210, 168, 140, 120, 105, 2520, 1260, 840, 630, 504, 420, 360, 315, 280, 2520, 1260, 840, 630, 504, 420, 360, 315, 280, 252, 27720, 13860, 9240

Offset: 1

Author

Leroy Quet, Jul 15 2006

Keywords

• nonn
• tabl

Comments

T(n,1) = A003418(n). Row sums yield A025529. - Emeric Deutsch, Jul 24 2006

Examples

			Triangle starts:
   1;
   2,  1;
   6,  3,  2;
  12,  6,  4,  3;
  60, 30, 20, 15, 12;
		

Links

• John Tyler Rascoe, Rows n = 1..140, flattened

Crossrefs

Cf. A003418, A025529, A094310.

Programs

Maple

T:=proc(n,k) if k<=n then lcm(seq(j,j=1..n))/k else 0 fi end: for n from 1 to 11 do seq(T(n,k),k=1..n) od; # yields sequence in triangular form); # Emeric Deutsch, Jul 24 2006

Python

from math import lcm
def A120435(maxrow):
    A,rlcm = [],1
    for n in range(1,maxrow+1):
        rlcm = lcm(n,rlcm)
        A.append(list(rlcm//k for k in range(1,n+1)))
    return A # John Tyler Rascoe, Nov 08 2024

Extensions

More terms from Emeric Deutsch, Jul 24 2006