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A219081 Hilltop maps: number of 4Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..1 4Xn array.

%I A219081 #6 Jul 23 2025 00:13:13
%S A219081 1,149,2469,32945,494713,7561349,113959413,1715622809,25868247057,
%T A219081 390055483301,5880485889397,88654851159857,1336593648057193,
%U A219081 20150953522466741,303802286301958197,4580222640012373465
%N A219081 Hilltop maps: number of 4Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..1 4Xn array.
%C A219081 Row 4 of A219078
%H A219081 R. H. Hardin, <a href="/A219081/b219081.txt">Table of n, a(n) for n = 1..142</a>
%F A219081 Empirical: a(n) = 10*a(n-1) +44*a(n-2) +384*a(n-3) +1502*a(n-4) +1612*a(n-5) -478*a(n-6) -4742*a(n-7) -13053*a(n-8) -13178*a(n-9) -7218*a(n-10) -8982*a(n-11) -108*a(n-12) +3888*a(n-13)
%e A219081 Some solutions for n=3
%e A219081 ..1..0..1....0..1..0....0..1..0....0..1..0....0..1..0....1..1..1....0..0..0
%e A219081 ..1..0..0....0..0..0....1..1..1....1..0..0....1..1..0....1..0..0....1..1..1
%e A219081 ..1..1..1....1..0..1....0..1..1....1..0..1....1..1..0....1..1..1....1..1..0
%e A219081 ..0..1..1....1..1..1....1..1..1....1..1..0....1..1..0....1..0..1....1..0..0
%K A219081 nonn
%O A219081 1,2
%A A219081 _R. H. Hardin_ Nov 11 2012