A237406 - OEIS

%I #8 Feb 07 2014 19:18:42

%S 322,1632,8236,44186,238640,1260486,6627450,35198148,187296514,

%T 992298282,5252792268,27863022136,147844066586,783716212410,

%U 4153931543322,22027680104792,116814804478526,619329438394524,3283506981597222

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

%C Column 2 of A237412.

%H R. H. Hardin, <a href="/A237406/b237406.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 35*a(n-3) +422*a(n-4) +861*a(n-5) +1775*a(n-6) +703*a(n-7) -24448*a(n-8) -61622*a(n-9) -68118*a(n-10) +25946*a(n-11) +456293*a(n-12) +865728*a(n-13) +610758*a(n-14) -676767*a(n-15) -3048586*a(n-16) -3041167*a(n-17) -326886*a(n-18) +2509173*a(n-19) +5909549*a(n-20) +3426904*a(n-21) -1802161*a(n-22) -2482842*a(n-23) -2687207*a(n-24) -458763*a(n-25) +1972154*a(n-26) +1952715*a(n-27) +779599*a(n-28) -268828*a(n-29) -154455*a(n-30) -76262*a(n-31) +51183*a(n-32) -16342*a(n-33) +5863*a(n-34) -1640*a(n-35) +614*a(n-36) +64*a(n-37).

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 07 2014