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A219078
T(n,k) = number of n X k binary arrays with every 0 a horizontal, diagonal or antidiagonal neighbor to some 1, n >= 1, k >= 1, read by antidiagonals.
15
1, 3, 1, 5, 11, 1, 9, 47, 41, 1, 17, 165, 337, 149, 1, 31, 625, 2321, 2469, 547, 1, 57, 2435, 17537, 32945, 18499, 2007, 1, 105, 9367, 134809, 494713, 477309, 137251, 7361, 1, 193, 35901, 1023441, 7561349, 14228041, 6879341, 1019123, 27001, 1, 355, 137865
OFFSET
1,2
COMMENTS
Original definition: T(n,k) = Hilltop maps: number of n X k binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..1 n X k array.
Number of dominating sets in an n X k grid graph with edges connecting horizontally, diagonally or antidiagonally adjacent vertices. - Andrew Howroyd, Jul 14 2026
LINKS
Eric Weisstein's World of Mathematics, Dominating Set.
EXAMPLE
Table starts:
1 3 5 9 17 31
1 11 47 165 625 2435
1 41 337 2321 17537 134809
1 149 2469 32945 494713 7561349
1 547 18499 477309 14228041 433704331
1 2007 137251 6879341 407374825 24734141495
1 7361 1019123 99118753 11660290321 1410242020653
1 27001 7573641 1428782305 333882416305 80444813963129
1 99043 56263253 20594013941 9559854123673 4588436794733591
1 363299 417979331 296830835781 273717397488937 261712432286491659
1 1332617 3105269893 4278398369137 7837125931615553 14927540586501299193
1 4888173 23069495037 61667023808785 224393896465841065 851435525780779197693
...
Some solutions for n=3 k=4:
..1..1..0..0....1..1..1..1....1..0..0..1....1..1..1..1....0..0..1..1
..0..0..1..0....1..0..0..1....1..1..0..0....1..1..1..0....1..1..1..0
..0..1..0..0....1..1..0..1....1..0..1..1....0..1..0..1....0..0..0..1
CROSSREFS
Main diagonal is A219072.
Sequence in context: A093905 A324017 A063853 * A266033 A105064 A073496
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 11 2012
EXTENSIONS
New name from Andrew Howroyd, Jul 14 2026
STATUS
approved