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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
1, 2, 5, 8, 11, 17, 21, 28, 35, 42, 51, 60, 69, 80, 91
OFFSET
1,2
LINKS
Dmitry Kamenetsky, Example solutions for n <= 11.
Puzzling StackExchange, Paint Eleven Squares, 2021.
CROSSREFS
Cf. A344301.
Sequence in context: A300272 A352143 A365808 * A192147 A226817 A154484
KEYWORD
nonn,hard,more
AUTHOR
Dmitry Kamenetsky, May 28 2021
EXTENSIONS
a(12)-a(15) from Bert Dobbelaere, Jun 13 2021
STATUS
approved