A344719 Minimum number of cells in an n X n grid that need to be painted so that each unpainted cell is orthogonally adjacent to exactly two painted cells.
1, 2, 5, 8, 11, 17, 21, 28, 35, 42, 51, 60, 69, 80, 91
Offset: 1
Links
- Dmitry Kamenetsky, Example solutions for n <= 11.
- Puzzling StackExchange, Paint Eleven Squares, 2021.
Crossrefs
Cf. A344301.
Extensions
a(12)-a(15) from Bert Dobbelaere, Jun 13 2021