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A210987
Number of fixed polyominoes with 2n-1 cells.
2
1, 6, 63, 760, 9910, 135268, 1903890, 27394666, 400795844, 5940738676, 88983512783, 1344372335524, 20457802016011, 313224032098244, 4820975409710116, 74541651404935148, 1157186142148293638, 18027932215016128134
OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Polyomino
Wikipedia, Polyomino
FORMULA
a(n) = A001168(2*n-1).
CROSSREFS
Bisection of A001168.
Sequence in context: A001261 A252813 A346581 * A341376 A234465 A231552
KEYWORD
nonn
AUTHOR
Omar E. Pol, Sep 16 2012
STATUS
approved