A237969 - OEIS

%I #4 Feb 16 2014 06:50:29

%S 7905,59014,369068,2609908,20123780,149625960,1103412332,8201125448,

%T 61392928964,454158172752,3384197190198,25127260995252,

%U 187313795410528,1387556859816504,10349189174713490,76751150630045768,572086176964557556

%N Number of (n+1)X(3+1) 0..3 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

%C Column 3 of A237974

%H R. H. Hardin, <a href="/A237969/b237969.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2894*a(n-4) +44487*a(n-6) -1503817*a(n-8) -30896235*a(n-10) +210299314*a(n-12) +4888817325*a(n-14) -14506815710*a(n-16) -273679187459*a(n-18) -437518653104*a(n-20) +9172444092579*a(n-22) +56036113474638*a(n-24) -195310008842740*a(n-26) -938665468143984*a(n-28) +2927054715784732*a(n-30) +2688466221818800*a(n-32) -21148892074250088*a(n-34) -56644046711903024*a(n-36) -9144467048901376*a(n-38) +77073773917450080*a(n-40) +63947939728517856*a(n-42) -43340863596329664*a(n-44) -24828004482833664*a(n-46) -1848578704883712*a(n-48) for n>53

%e Some solutions for n=2

%e ..3..2..2..1....3..0..2..3....2..0..1..1....3..2..0..1....0..3..3..1

%e ..3..1..0..0....3..1..3..2....0..0..2..3....2..3..0..1....1..2..0..2

%e ..2..2..0..1....2..1..1..2....1..1..2..3....2..1..0..0....0..0..3..3

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 16 2014