A337502 - OEIS

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A337502

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

0, 1, 3, 6, 9, 15, 20, 27, 34, 43 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,3`
	LINKS	`Table of n, a(n) for n=1..10.`
	EXAMPLE	`For n = 4, painting only 5 cells would leave an unpainted tetromino, but painting the following 6 cells avoids all unpainted tetrominoes:` `. . X .` `X X . X` `. . X .` `. X . .`
	CROSSREFS	`Cf. A337501.` `Sequence in context: A143981 A031940 A007187 * A082004 A112773 A070885` `Adjacent sequences: A337499 A337500 A337501 * A337503 A337504 A337505`
	KEYWORD	`nonn,more`
	AUTHOR	`Rob Pratt, Aug 29 2020`
	STATUS	`approved`

Last modified February 27 05:37 EST 2021. Contains 341649 sequences. (Running on oeis4.)