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A120108 Number triangle lcm(1,..,n+1)/lcm(1,..,k+1). 3
1, 2, 1, 6, 3, 1, 12, 6, 2, 1, 60, 30, 10, 5, 1, 60, 30, 10, 5, 1, 1, 420, 210, 70, 35, 7, 7, 1, 840, 420, 140, 70, 14, 14, 2, 1, 2520, 1260, 420, 210, 42, 42, 6, 3, 1, 2520, 1260, 420, 210, 42, 42, 6, 3, 1, 1, 27720, 13860, 4620, 2310, 462, 462, 66, 33, 11, 11, 1 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

First column is A003418(n+1). Second column is A025555. Row sums are A120109. Diagonal sums are A120110. Inverse is A120111.

FORMULA

Number triangle T(n,k)=[k<=n]*lcm(1,..,n+1)/lcm(1,..,k+1)

EXAMPLE

Triangle begins

1,

2, 1,

6, 3, 1,

12, 6, 2, 1,

60, 30, 10, 5, 1,

60, 30, 10, 5, 1, 1,

420, 210, 70, 35, 7, 7, 1

CROSSREFS

Sequence in context: A065553 A016545 A142977 * A060556 A132813 A034898

Adjacent sequences:  A120105 A120106 A120107 * A120109 A120110 A120111

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Jun 09 2006

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Last modified February 15 20:03 EST 2012. Contains 205852 sequences.