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A261752 Minimum number of knights on an n X n chessboard such that every square is attacked. 2
6, 7, 8, 10, 14, 18, 22, 25, 28, 32, 36, 43, 48, 54, 58, 66, 70, 78, 84, 91, 98, 107, 112, 123, 128, 139, 146, 156, 164 (list; graph; refs; listen; history; text; internal format)
OFFSET
4,1
COMMENTS
Total domination number of n X n knight graph.
Distinct from A006075 since here all squares must be attacked, whereas, in A006075, all squares are either attacked or occupied.
a(34) = 182, a(36) = 202, a(38) = 224. - Andy Huchala, Jun 04 2021
LINKS
Andy Huchala, Python program
Eric Weisstein's World of Mathematics, Knight Graph
Eric Weisstein's World of Mathematics, Total Domination Number
EXAMPLE
An example for the 4 X 4 case:
....
.NNN
.N..
NN..
and for the 5 x 5 case:
.....
..N..
.NN..
NNN..
N....
CROSSREFS
Cf. A006075.
Sequence in context: A031237 A031314 A209723 * A248902 A295668 A274556
KEYWORD
nonn,more
AUTHOR
Matthew Conroy, Aug 31 2015
EXTENSIONS
a(15)-a(18) from Giovanni Resta, Aug 31 2015
a(19)-a(26) from Andy Huchala, Oct 16 2017
a(27)-a(30) from Andy Huchala, Oct 18 2017
a(31)-a(32) from Andy Huchala, Jun 04 2021
STATUS
approved

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Last modified February 29 17:04 EST 2024. Contains 370427 sequences. (Running on oeis4.)