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A131843 Triangle read by rows: 2*A131821 - A000012. 4
1, 3, 3, 5, 1, 5, 7, 1, 1, 7, 9, 1, 1, 1, 9, 11, 1, 1, 1, 1, 11, 13, 1, 1, 1, 1, 1, 13, 15, 1, 1, 1, 1, 1, 1, 15, 17, 1, 1, 1, 1, 1, 1, 1, 17, 19, 1, 1, 1, 1, 1, 1, 1, 1, 19, 21, 1, 1, 1, 1, 1, 1, 1, 1, 1, 21, 23, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 23, 25, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 25, 27, 1, 1, 1, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums = 5*n + 1, A016861: (1, 6, 11, 16, 21,...).

LINKS

B. D. Swan, Table of n, a(n) for n=0,...,100000

FORMULA

2*A131821 - A000012 as an infinite lower triangular matrix. 2*n - 1, (1, 3, 5, 7,...) as right and left borders, with the rest zeros.

EXAMPLE

First few rows of the triangle are:

1;

3, 3;

5, 1, 5;

7, 1, 1, 7;

9, 1, 1, 1, 9;

11, 1, 1, 1, 1, 11;

...

CROSSREFS

Cf. A131821, A016861.

Sequence in context: A205853 A240594 A079887 * A205550 A209389 A105104

Adjacent sequences:  A131840 A131841 A131842 * A131844 A131845 A131846

KEYWORD

nonn,tabl,easy

AUTHOR

Gary W. Adamson, Jul 21 2007

EXTENSIONS

Corrected and edited by B. D. Swan (bdswan(AT)gmail.com), Dec 20 2008

STATUS

approved

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Last modified December 18 22:55 EST 2014. Contains 252174 sequences.