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A143956
Triangle read by rows, A000012 * A136521 * A000012; 1<=k<=n.
0
1, 3, 2, 5, 4, 2, 7, 6, 4, 2, 9, 8, 6, 4, 2, 11, 10, 8, 6, 4, 2, 13, 12, 10, 8, 6, 4, 2, 15, 14, 12, 10, 8, 6, 4, 2, 17, 16, 14, 12, 10, 8, 6, 4, 2, 19, 18, 16, 14, 12, 10, 8, 6, 4, 2, 21, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2
OFFSET
1,2
COMMENTS
Row sums = A028387: (1, 5, 11, 19, 29, 41,...)
FORMULA
Triangle read by rows, A000012 * A136521 * A000012; 1<=k<=n. A136521 = an infinite lower triangular matrix with (1,2,2,2,...) in the main diagonal the rest zeros.
EXAMPLE
First few rows of the triangle =
1;
3, 2;
5, 4, 2;
7, 6, 4, 2;
9, 8, 6, 4, 2;
11, 10, 8, 6, 4, 2;
13, 12, 10, 8, 6, 4, 2;
15, 14, 12, 10, 8, 6, 4, 2;
...
CROSSREFS
Sequence in context: A363447 A371905 A371908 * A110661 A143124 A205400
KEYWORD
nonn,tabl
AUTHOR
STATUS
approved