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A120435
Triangle read by rows: T(n,k) = lcm(1,2,3,4,...,n)/k (1 <= k <= n).
0
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
1,2
COMMENTS
T(n,1) = A003418(n). Row sums yield A025529. - Emeric Deutsch, Jul 24 2006
LINKS
John Tyler Rascoe, Rows n = 1..140, flattened
EXAMPLE
Triangle starts:
1;
2, 1;
6, 3, 2;
12, 6, 4, 3;
60, 30, 20, 15, 12;
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
PROG
(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
CROSSREFS
KEYWORD
nonn,tabl,changed
AUTHOR
Leroy Quet, Jul 15 2006
EXTENSIONS
More terms from Emeric Deutsch, Jul 24 2006
STATUS
approved