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A057424 Diagonally symmetric (about diagonal 2) 2n-celled polyominoes with 1 hole. 0
1, 1, 5, 7, 21, 30, 88, 116, 336 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,3

LINKS

Table of n, a(n) for n=6..14.

Tomás Oliveira e Silva, Enumeration of polyominoes

CROSSREFS

Sequence in context: A120035 A198302 A091154 * A027152 A076197 A002596

Adjacent sequences:  A057421 A057422 A057423 * A057425 A057426 A057427

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 05 2000

STATUS

approved

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Last modified July 17 08:42 EDT 2019. Contains 325098 sequences. (Running on oeis4.)