A337501 Minimum number of painted cells in an n X n grid to avoid unpainted trominoes.

0, 2, 4, 8, 11, 18, 23, 32, 39, 50

Offset: 1

Author

Rob Pratt, Aug 29 2020

Keywords

• nonn
• more

Examples

			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