A218201 - OEIS

%I #4 Oct 23 2012 08:43:08

%S 7,59,483,3841,30599,243953,1945103,15508803,123654745,985923281,

%T 7860958915,62676962321,499735676361,3984490261291,31769119935801,

%U 253301405031061,2019621630078545,16102838151192633,128391077151131153

%N Hilltop maps: number of nX3 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..2 nX3 array

%C Column 3 of A218206

%H R. H. Hardin, <a href="/A218201/b218201.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) +6*a(n-2) +12*a(n-3) +10*a(n-4) +48*a(n-5) +9*a(n-6) +5*a(n-7) +13*a(n-8) +11*a(n-9) -51*a(n-10) -59*a(n-11) -48*a(n-12) -38*a(n-13) +13*a(n-14) +39*a(n-15) +33*a(n-16) +15*a(n-17) +5*a(n-18) -5*a(n-19) -6*a(n-20) -2*a(n-21) +2*a(n-22) -a(n-24) -a(n-25)

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Oct 23 2012