A218202 - OEIS

%I #4 Oct 23 2012 08:43:55

%S 13,233,3841,61013,971849,15491481,246985085,3937780585,62780737565,

%T 1000923719573,15957894038581,254419385085069,4056251066250069,

%U 64669493117015921,1031036607295654341,16437990067341484021

%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..2 nX4 array

%C Column 4 of A218206

%H R. H. Hardin, <a href="/A218202/b218202.txt">Table of n, a(n) for n = 1..207</a>

%F Empirical: a(n) = 14*a(n-1) +24*a(n-2) +89*a(n-3) +228*a(n-4) +1982*a(n-5) +669*a(n-6) +1250*a(n-7) +4654*a(n-8) +4729*a(n-9) -22038*a(n-10) -25904*a(n-11) -29844*a(n-12) -57012*a(n-13) +65721*a(n-14) +52590*a(n-15) +35734*a(n-16) +8989*a(n-17) +12238*a(n-18) -21246*a(n-19) +21741*a(n-20) -10230*a(n-21) -2270*a(n-22) -11169*a(n-23) -2188*a(n-24) -12892*a(n-25) +12246*a(n-26) -9470*a(n-27) -380*a(n-28) -370*a(n-29) -7800*a(n-30) -9822*a(n-31) +891*a(n-32) -1042*a(n-33) -5568*a(n-34) +121*a(n-35) +642*a(n-36) +52*a(n-37) +1077*a(n-38) +1104*a(n-39) -74*a(n-40) +415*a(n-41) +700*a(n-42) +134*a(n-43) +64*a(n-44) +90*a(n-45) +43*a(n-46) +48*a(n-47) +24*a(n-48) -5*a(n-49) -2*a(n-50) +4*a(n-51) -3*a(n-52) -a(n-55)

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Oct 23 2012