The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 Table of n, a(n) for n=4..32. Matthew Conroy, Examples of minimum knight arrangements, n = 4 through n = 14 Andy Huchala, Python program Giovanni Resta, Examples of minimum knight arrangements, from n = 15 to n = 18 Andy Huchala, Examples of minimum knight arrangements, from n = 25 to n = 34 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 Adjacent sequences: A261749 A261750 A261751 * A261753 A261754 A261755 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

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