A233499 - OEIS

%I #7 Mar 15 2023 15:33:47

%S 424009,26851581,1709348346,108934667695,6940835448966,

%T 442240878862773,28176593184596215,1795219762788597690,

%U 114378735336956365968,7287404963779880864407,464301857642373045877140

%N Number of (2+2) X (n+2) 0..2 arrays with no increasing sequence of length 3 horizontally or antidiagonally downwards.

%C Row 2 of A233497.

%H R. H. Hardin, <a href="/A233499/b233499.txt">Table of n, a(n) for n = 1..210</a>

%H R. H. Hardin, <a href="/A233499/a233499.txt">Empirical recurrence of order 68</a>

%F Empirical recurrence of order 68 (see link above).

%e Some solutions for n=1

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

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

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

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

%Y Cf. A233497.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 11 2013