A250928 - OEIS

%I #12 Nov 23 2018 21:18:10

%S 164,1652,16588,166600,1673388,16808096,168826024,1695743636,

%T 17032602828,171081026028,1718393703032,17260107602388,

%U 173366158128632,1741346315841920,17490651142232804,175681812742310068

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

%H R. H. Hardin, <a href="/A250928/b250928.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 12*a(n-1) - 23*a(n-2) + 37*a(n-3) - 33*a(n-4).

%F Empirical g.f.: 4*x*(41 - 79*x + 134*x^2 - 132*x^3) / (1 - 12*x + 23*x^2 - 37*x^3 + 33*x^4). - _Colin Barker_, Nov 23 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Column 1 of A250935.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 28 2014