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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
OFFSET
0,2
COMMENTS
Row sums = 5*n + 1, A016861: (1, 6, 11, 16, 21, ...).
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
Sequence in context: A205853 A240594 A079887 * A205550 A209389 A337544
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