

A239231


Heyawake numbers: maximum number of painted cells in an n X n grid, such that no two painted cells are orthogonally adjacent and the unpainted cells form a contiguous area.


2



0, 1, 1, 4, 5, 9, 12, 17, 21, 27, 33, 41, 48, 56, 65, 75, 85, 96, 108, 121, 133, 146, 161, 176, 190, 208
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OFFSET

0,4


COMMENTS

Inspired by the Japanese puzzle of the same name.


LINKS



FORMULA



EXAMPLE

For example, if n=6, the painted cells could be A1, A3, A6, B5, C1, C3, D4, D6, E2, F1, F4, F6 (12 cells in all).


CROSSREFS

Cf. A239072 (makes up the inner n4 X n4 square of the grid).


KEYWORD

nonn,more


AUTHOR



EXTENSIONS

Some values corrected, incorrect values removed by Elliott Line, Aug 21 2014
a(16) and a(20) corrected by Elliott Line at suggestion of Greg Malen, Sep 02 2020


STATUS

approved



