A251802 Number of (2+1)X(n+1) 0..3 arrays with no 2X2 subblock having x11-x00 less than x10-x01.

1740, 28932, 348679, 3352272, 27291608, 195753488, 1271711747, 7634258216, 42987423526, 229660644080, 1174599406053, 5792185593840, 27697451048182, 129039115827548, 587993778478925, 2629056738236432, 11566062999511464

Offset: 1

Author

R. H. Hardin, Dec 09 2014

Keywords

• nonn

Comments

Row 2 of A251801

Examples

			Some solutions for n=2
..3..3..2....1..1..0....2..3..2....0..3..0....2..1..2....0..3..3....2..2..1
..0..1..3....0..1..3....0..0..3....0..0..3....2..3..2....0..0..3....1..1..3
..0..0..0....0..2..0....0..1..0....1..1..1....1..0..2....0..1..3....0..1..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 40*a(n-1) -755*a(n-2) +8946*a(n-3) -74677*a(n-4) +467156*a(n-5) -2274363*a(n-6) +8833486*a(n-7) -27833039*a(n-8) [phone]*a(n-9) -153781873*a(n-10) [phone]*a(n-11) -402324879*a(n-12) [phone]*a(n-13) -498877265*a(n-14) [phone]*a(n-15) -280100140*a(n-16) [phone]*a(n-17) -63500432*a(n-18) [phone]*a(n-19) -4463424*a(n-20) +625536*a(n-21) -41472*a(n-22)