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A057418
Number of n-celled free polyominoes with 1 hole.
8
1, 6, 37, 195, 975, 4622, 21128, 94109, 410820, 1766591, 7506179, 31596240, 131991619, 547992183, 2263477612, 9309386178, 38150082057, 155859235424, 635067478628, 2581737704039, 10474587325120, 42422970467980
OFFSET
7,2
CROSSREFS
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Sep 05 2000
EXTENSIONS
a(27)-a(28) from Tomás Oliveira e Silva's page added by Andrei Zabolotskii, Sep 15 2025
STATUS
approved