login
A337501
Minimum number of painted cells in an n X n grid to avoid unpainted trominoes.
3
0, 2, 4, 8, 11, 18, 23, 32, 39, 50
OFFSET
1,2
EXAMPLE
For n = 3, painting only 3 cells would leave an unpainted tromino, but painting the following 4 cells avoids all unpainted trominoes:
. . X
X X .
. . X
CROSSREFS
Sequence in context: A120632 A007295 A053439 * A365922 A373080 A180379
KEYWORD
nonn,more
AUTHOR
Rob Pratt, Aug 29 2020
STATUS
approved