A234374 - OEIS

%I #5 Dec 25 2013 09:45:24

%S 16584,372690,8280018,183669567,4070647527,90202925160,1998695595393,

%T 44285957330064,981257012375877,21741969563527710,481742279623346310,

%U 10674083235829126662,236508300027959898666,5240372784459502455399

%N Number of (n+2)X(1+2) 0..2 arrays with no increasing sequence of length 3 horizontally or diagonally downwards

%C Column 1 of A234380

%H R. H. Hardin, <a href="/A234374/b234374.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 25*a(n-1) -a(n-2) -1496*a(n-3) +1581*a(n-4) +26414*a(n-5) -21436*a(n-6) -163909*a(n-7) +88557*a(n-8) +442265*a(n-9) -137417*a(n-10) -545671*a(n-11) +88129*a(n-12) +301041*a(n-13) -29854*a(n-14) -68212*a(n-15) +5810*a(n-16) +3264*a(n-17) -396*a(n-18) +36*a(n-19)

%e Some solutions for n=1

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 25 2013