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A275869
Number of nonequivalent ways to place k>=0 nonattacking kings on an n X n board.
2
2, 2, 11, 51, 922, 25618, 1597350, 169413040, 33716225195, 11838480390673, 7588965091313449, 8705702554970941096, 18079208010076976255573, 67519585404524909086260614, 455193583190737164106702088892, 5527752160260327852724215089473548
OFFSET
1,1
COMMENTS
Also number of nonequivalent ways to tile an n+1 X n+1 square with 1 X 1 and 2 X 2 tiles.
Also row sum of triangle A236679.
Rotations and reflections of a placement are not counted. If they are to be counted, see A063443.
LINKS
CROSSREFS
Sequence in context: A192824 A184237 A069648 * A175976 A095215 A264712
KEYWORD
nonn
AUTHOR
Heinrich Ludwig, Dec 11 2016
EXTENSIONS
a(10)-a(16) from Andrew Howroyd, May 30 2017
STATUS
approved