A234394 - OEIS

%I #4 Dec 25 2013 11:15:04

%S 196316,10683130,585790562,32129615500,1761338821822,96553476935058,

%T 5293088906692756,290169408255194858,15907169753200518438,

%U 872035377995319811964,47805225784776928099734,2620696036046778403201050

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

%C Row 1 of A234393

%H R. H. Hardin, <a href="/A234394/b234394.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 59*a(n-1) -321*a(n-2) +5250*a(n-3) +11912*a(n-4) -1362734*a(n-5) +2774640*a(n-6) +51543392*a(n-7) -111860552*a(n-8) -142606384*a(n-9) -375586128*a(n-10) -4285167120*a(n-11) +4322222432*a(n-12) -4985269824*a(n-13) +9926880896*a(n-14) +25978108928*a(n-15) -24346223616*a(n-16) +12931098624*a(n-17) -20510392320*a(n-18) -28179726336*a(n-19) +22454599680*a(n-20)

%e Some solutions for n=1

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 25 2013