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A243510
Number of ways the maximal number of domicules can be placed on an n X n square.
3
1, 1, 3, 58, 280, 170985, 3037561, 35203565096, 3263262629905, 580992839261272720, 326207195516663381931, 811740344447523575023878026, 3011882198082438957330143630563, 98662906581850761030365769529236858241, 2565014347691062208319404612723752103028288
OFFSET
0,3
COMMENTS
Number of maximum matchings in the n X n king graph. - Eric W. Weisstein, Jun 20 2017
LINKS
Eric Weisstein's World of Mathematics, Independent Edge Set
Eric Weisstein's World of Mathematics, King Graph
Eric Weisstein's World of Mathematics, Matching
Eric Weisstein's World of Mathematics, Maximum Independent Edge Set
Wikipedia, King's graph
FORMULA
a(n) = A243424(n,floor(n^2/2)).
EXAMPLE
a(2) = 3:
+---+ +---+ +---+
|o-o| |o o| |o o|
| | || || | X |
|o-o| |o o| |o o|
+---+ +---+ +---+.
a(3) = 58:
+-----+ +-----+ +-----+
|o-o o| |o o o| |o o-o|
| || | X || | \ |
|o o| |o o o| |o o o|
|| | | | || / |
|o o-o| |o-o | |o o |
+-----+ +-----+ +-----+ ... .
CROSSREFS
Cf. A243511.
Even bisection gives A239273.
Sequence in context: A041735 A156487 A254653 * A024218 A049661 A295409
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 05 2014
STATUS
approved