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A128140
1
1, 3, 2, 7, 5, 3, 13, 10, 7, 4, 21, 17, 13, 9, 5, 31, 26, 21, 16, 11, 6, 43, 37, 31, 25, 19, 13, 7, 57, 50, 43, 36, 29, 22, 15, 8, 73, 65, 57, 49, 41, 33, 25, 17, 9, 91, 82, 73, 64, 55, 46, 37, 28, 19, 10
OFFSET
1,2
COMMENTS
Row sums = A006003, starting (1, 5, 15, 34, 65, 111, ...). Left border = A002061: (1, 3, 7, 13, 21, 31, 43, ...) A128139 = A004736 * A128132
FORMULA
A128132 * A004736 as infinite lower triangular matrices.
EXAMPLE
First few rows of the triangle:
1;
3, 2;
7, 5, 3;
13, 10, 7, 4;
21, 17, 13, 9, 5;
31, 26, 21, 16, 11, 6;
43, 37, 31, 25, 19, 13, 7;
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Feb 16 2007
STATUS
approved