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A218426 T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, vertical or antidiagonal neighbor in a random 0..1 nXk array.

%I A218426 #6 Jul 22 2025 23:57:13
%S A218426 1,3,3,5,13,5,9,49,49,9,17,191,357,191,17,31,737,2725,2725,737,31,57,
%T A218426 2849,20793,41515,20793,2849,57,105,11011,158429,629659,629659,158429,
%U A218426 11011,105,193,42557,1207525,9539915,19003811,9539915,1207525,42557,193
%N A218426 T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, vertical or antidiagonal neighbor in a random 0..1 nXk array.
%C A218426 Table starts
%C A218426 ....1.......3...........5...............9.................17
%C A218426 ....3......13..........49.............191................737
%C A218426 ....5......49.........357............2725..............20793
%C A218426 ....9.....191........2725...........41515.............629659
%C A218426 ...17.....737.......20793..........629659...........19003811
%C A218426 ...31....2849......158429.........9539915..........572765605
%C A218426 ...57...11011.....1207525.......144597047........17270172871
%C A218426 ..105...42557.....9203377......2191517757.......520703946625
%C A218426 ..193..164481....70144889.....33214850067.....15699497444771
%C A218426 ..355..635711...534620525....503408006597....473348740584743
%C A218426 ..653.2456993..4074695269...7629705089721..14271727157207365
%C A218426 .1201.9496161.31055936969.115636627121941.430300515162577777
%H A218426 R. H. Hardin, <a href="/A218426/b218426.txt">Table of n, a(n) for n = 1..263</a>
%e A218426 Some solutions for n=3 k=4
%e A218426 ..1..0..1..1....0..1..0..1....1..1..1..0....1..1..0..1....1..0..0..1
%e A218426 ..0..1..0..1....0..0..0..0....0..0..1..0....0..0..1..0....0..1..0..0
%e A218426 ..1..1..1..1....1..1..0..1....1..1..0..1....1..1..0..1....0..1..1..1
%Y A218426 Column 1 is A000213(n+1)
%K A218426 nonn,tabl
%O A218426 1,2
%A A218426 _R. H. Hardin_ Oct 28 2012