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A056881 Number of n-celled diagonally symmetric polyominoes without holes. 0
0, 0, 1, 0, 2, 2, 6, 5, 21, 18, 70, 61, 239, 206, 828, 711, 2903, 2485, 10314, 8791, 37031, 31451, 134147, 113566, 489672, 413419, 1799084, 1515282 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Table of n, a(n) for n=1..28.

Tomás Oliveira e Silva, Enumeration of polyominoes

CROSSREFS

Sequence in context: A111419 A306768 A174399 * A260322 A286540 A229980

Adjacent sequences:  A056878 A056879 A056880 * A056882 A056883 A056884

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 03 2000

STATUS

approved

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Last modified April 17 10:23 EDT 2021. Contains 343064 sequences. (Running on oeis4.)