login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A120108 Number triangle T(n,k) = lcm(1,..,n+1)/lcm(1,..,k+1). 4
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; text; internal format)
OFFSET

0,2

LINKS

Muniru A Asiru, Rows n=0..100 of triangle, flattened

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;

MAPLE

T:= (n, k)-> ilcm(seq(q, q=1..n+1))/ilcm(seq(r, r=1..k+1)):

seq(seq(T(n, k), k=0..n), n=0..10); # Muniru A Asiru, Feb 26 2019

PROG

(GAP) Flat(List([0..10], n->List([0..n], k->Lcm(List([1..n+1], i->i))/Lcm(List([1..k+1], i->i))))); # Muniru A Asiru, Feb 26 2019

CROSSREFS

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

Sequence in context: A065553 A016545 A142977 * A060556 A222969 A132813

Adjacent sequences:  A120105 A120106 A120107 * A120109 A120110 A120111

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Jun 09 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 6 11:38 EDT 2020. Contains 333273 sequences. (Running on oeis4.)