A218350 - OEIS

%I #4 Oct 26 2012 19:28:32

%S 9,149,2069,28661,401253,5609569,78394141,1095695529,15314367301,

%T 214044940145,2991651891557,41813576818545,584417958076589,

%U 8168264238929833,114165795446827469,1595666897305379897

%N Hilltop maps: number of nX4 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..1 nX4 array

%C Column 4 of A218354

%H R. H. Hardin, <a href="/A218350/b218350.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 10*a(n-1) +36*a(n-2) +242*a(n-3) +413*a(n-4) +482*a(n-5) -720*a(n-6) -2212*a(n-7) -683*a(n-8) +466*a(n-9) +121*a(n-10) -414*a(n-11) -119*a(n-12) -100*a(n-13) +241*a(n-14) +36*a(n-15) +164*a(n-16) -44*a(n-17) +35*a(n-18) -4*a(n-19) +2*a(n-20) +2*a(n-21) -a(n-22)

%e Some solutions for n=3

%e ..1..0..0..1....0..1..1..1....1..0..0..1....1..1..0..1....1..1..1..0

%e ..0..0..1..1....0..1..0..1....1..1..1..1....1..1..1..1....0..0..1..1

%e ..0..1..1..1....1..1..1..0....0..1..0..0....0..1..1..1....0..1..0..1

%K nonn

%O 1,1

%A _R. H. Hardin_ Oct 26 2012