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A131421 (A000012 * A127775) + (A127775 * A000012) - A000012. 0
1, 3, 5, 5, 7, 9, 7, 9, 11, 13, 9, 11, 13, 15, 17, 11, 13, 15, 17, 19, 21, 13, 15, 17, 19, 21, 23, 25, 15, 17, 19, 21, 23, 25, 27, 29, 17, 19, 21, 23, 25, 27, 39, 31, 33, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Row sums = A000567, the octagonal numbers: (1, 8, 21, 40, 65, 96,...).

FORMULA

(A000012 * A127775) + (A127775 * A000012) - A000012; as infinite lower triangular matrices.

EXAMPLE

First few rows of the triangle are:

1;

3, 5;

5, 7, 9;

7, 9, 11, 13;

9, 11, 13, 15, 17;

11, 13, 15, 17, 19, 21;

13, 15, 17, 19, 21, 23, 25;

...

CROSSREFS

Cf. A127775, A000567.

Sequence in context: A138475 A195990 A023840 * A088743 A168056 A122800

Adjacent sequences:  A131418 A131419 A131420 * A131422 A131423 A131424

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 10 2007

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Last modified February 17 09:09 EST 2012. Contains 206002 sequences.