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A130461 Triangle, antidiagonals of an array generated from A130460. 3
1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 3, 1, 1, 1, 2, 6, 4, 1, 1, 1, 2, 6, 12, 5, 1, 1, 1, 2, 6, 24, 20, 6, 1, 1, 1, 2, 6, 24, 60, 30, 7, 1, 1, 1, 2, 6, 24, 120, 120, 42, 8, 1, 1, 1, 2, 6, 24, 120, 360, 210, 56, 9, 1, 1, 1, 2, 6, 24, 120, 720, 840, 336, 72, 10, 1, 1, 1, 2, 6, 24, 120, 720, 2520 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,9

COMMENTS

Rows tend to the factorials: (1, 1, 2, 6, 24,...). Row sums = A130476: (1, 2, 3, 5, 8, 15, 28, 61, 132,...).

LINKS

Table of n, a(n) for n=0..85.

FORMULA

Let A130460 = M, an infinite lower triangular matrix and V = [1, 1, 1,...], the first row of an array. Perform M * V = second row,...; (n+1)-th row = M * n-th row. The triangle = antidiagonals of the array.

EXAMPLE

The array =

1,...1,...1,...1,....1,....1,...

1,...1,...2,...3,....4,....5,...

1,...1,...2,...6,...12,...20,...

1,...1,...2,...6,...24,...60,...

1,...1,...2,...6,...24,..120,...

1,...1,...2,...6,...24,..120,...

...

First few rows of the triangle are:

1;

1, 1;

1, 1, 1;

1, 1, 2, 1;

1, 1, 2, 3, 1;

1, 1, 2, 6, 4, 1;

1, 1, 2, 6, 12, 5, 1;

1, 1, 2, 6, 24, 20, 6, 1;

1, 1, 2, 6, 24, 60, 30, 7, 1;

...

CROSSREFS

Cf. A130460, A130476, A130477, A130478.

Sequence in context: A238888 A179748 A096670 * A225631 A267482 A130777

Adjacent sequences:  A130458 A130459 A130460 * A130462 A130463 A130464

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, May 28 2007

EXTENSIONS

a(23) and a(38) corrected by Gionata Neri, Jun 22 2016

STATUS

approved

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Last modified October 24 06:43 EDT 2017. Contains 293836 sequences.