A251353 - OEIS

%I #4 Dec 01 2014 19:57:10

%S 2920,137642,6505867,307396791,14522811996,686136478104,

%T 32416955585740,1531558664946401,72359402605644368,

%U 3418663231755377792,161516789161897931030,7630957302185381871107,360529141480763613554961

%N Number of (n+1)X(2+1) 0..3 arrays with no 2X2 subblock having its maximum diagonal element less than the absolute difference of its antidiagonal elements

%C Column 2 of A251359

%H R. H. Hardin, <a href="/A251353/b251353.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 64*a(n-1) -996*a(n-2) +11578*a(n-3) -101830*a(n-4) +565355*a(n-5) -1946836*a(n-6) +4382875*a(n-7) -7058116*a(n-8) +8578826*a(n-9) -2416016*a(n-10) -37859617*a(n-11) +159993227*a(n-12) -380786469*a(n-13) +627428234*a(n-14) -768933079*a(n-15) +716269935*a(n-16) -490794809*a(n-17) +216766686*a(n-18) -25791720*a(n-19) -53590442*a(n-20) +66325899*a(n-21) -49766753*a(n-22) +26021030*a(n-23) -9346626*a(n-24) +2208580*a(n-25) -306048*a(n-26) +18432*a(n-27)

%e Some solutions for n=2

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 01 2014