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A338212 a(n) is the number of fixed polyominoes with sprawl n. 3

%I

%S 1,0,0,0,0,1,0,0,2,0,4,2,9,9,22,32,66,104,200,348,646,1172,2144,3964,

%T 7285,13581,25136,47070,87700,164764,309308,582152,1098698,2074484

%N a(n) is the number of fixed polyominoes with sprawl n.

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

%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a338/A338212.java">Java program</a> (github)

%F Antidiagonal sums of A338210.

%Y Cf. A001168, A338210, A338213.

%K nonn,more

%O 0,9

%A _Sean A. Irvine_ and _Allan C. Wechsler_, Oct 17 2020

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Last modified March 5 16:55 EST 2021. Contains 341827 sequences. (Running on oeis4.)