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A338212 a(n) is the number of fixed polyominoes with sprawl n. 3
1, 0, 0, 0, 0, 1, 0, 0, 2, 0, 4, 2, 9, 9, 22, 32, 66, 104, 200, 348, 646, 1172, 2144, 3964, 7285, 13581, 25136, 47070, 87700, 164764, 309308, 582152, 1098698, 2074484 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,9

COMMENTS

The sprawl of a polyomino is the number of cells in a polyomino plus the number of cells adjacent to it.

LINKS

Table of n, a(n) for n=0..33.

Sean A. Irvine, Java program (github)

FORMULA

Antidiagonal sums of A338210.

CROSSREFS

Cf. A001168, A338210, A338213.

Sequence in context: A068773 A234312 A244136 * A337451 A133168 A145382

Adjacent sequences:  A338209 A338210 A338211 * A338213 A338214 A338215

KEYWORD

nonn,more

AUTHOR

Sean A. Irvine and Allan C. Wechsler, Oct 17 2020

STATUS

approved

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Last modified January 22 13:06 EST 2021. Contains 340362 sequences. (Running on oeis4.)