OFFSET
1,4
COMMENTS
LINKS
Heinrich Ludwig, Table of n, a(n) for n = 1..165
EXAMPLE
The triangle begins:
1, 1;
1, 3, 3;
1, 6, 15, 15, 3;
1, 10, 45, 107, 128, 63, 10,
1, 15, 105, 428, 1062, 1566, 1276, 507, 69,
1, 21, 210, 1282, 5160, 13971, 25191, 29235, 20508, 7747, 1251, 42, 1;
...
There is T(6, 12) = 1 way to place 12 points (x) on the grid obeying the rule in the definition of the sequence:
.
x x
x . x
x . . x
x . . . x
. x x x x .
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Heinrich Ludwig, Jun 09 2014
STATUS
approved