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A127779 Triangle read by rows: A004736 * A127773. 2
1, 2, 3, 3, 6, 6, 4, 9, 12, 10, 5, 12, 18, 20, 15, 6, 15, 24, 30, 30, 21, 7, 18, 30, 40, 45, 42, 28, 8, 21, 36, 50, 60, 63, 56, 36, 9, 24, 42, 60, 75, 84, 84, 72, 45 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = bin(n,4), (A000332): (1, 5, 15, 35,...).

Contribution from Clark Kimberling, Sep 16 2008: (Start)

As a rectangular array: R=A000027*A000217; R(m,n)=n*C(m+1,2).

A127779 (rectangular) is the accumulation array (Cf. A144112) of

A002260 (rectangular, with n-th row (n,n,n,n,...). (End)

LINKS

Table of n, a(n) for n=1..45.

FORMULA

A004736 * A127773 as infinite lower triangular matrices.

EXAMPLE

First few rows of the triangle are:

1;

2, 3;

3, 6, 6;

4, 9, 12, 10;

5, 12, 18, 20, 15;

6, 15, 24, 30, 30, 21;

7, 18, 30, 40, 45, 42, 28;

...

CROSSREFS

Cf. A004736, A127773, A000217, A000332.

Cf. A002260. [From Clark Kimberling, Sep 16 2008]

Sequence in context: A075258 A321745 A212629 * A207634 A222862 A101437

Adjacent sequences:  A127776 A127777 A127778 * A127780 A127781 A127782

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Jan 28 2007

STATUS

approved

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Last modified September 20 01:54 EDT 2020. Contains 337260 sequences. (Running on oeis4.)