A208860 Number of nX4 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or left-upward diagonal neighbors.

15, 1691, 273049, 44452082, 7240366702, 1179377179523, 192108983085145, 31292693945057258, 5097277404701734234, 830297232890575975631, 135247396001465780031025, 22030493903508619572329906

Offset: 1

Author

R. H. Hardin Mar 02 2012

Keywords

• nonn

Comments

Column 4 of A208864

Examples

			Some solutions for n=4
..0..0..1..0....0..0..1..2....0..0..0..0....0..1..1..0....0..0..0..1
..0..2..2..0....0..3..3..0....1..1..1..1....0..1..2..0....1..1..1..2
..2..3..3..0....1..0..1..2....2..2..2..3....0..2..1..1....2..2..2..0
..1..2..0..2....1..2..0..0....0..1..3..0....3..1..0..0....0..3..0..1
		

Links

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

Formula

Empirical: a(n) = 219*a(n-1) -10289*a(n-2) +197167*a(n-3) -1651023*a(n-4) +4615685*a(n-5) +5157645*a(n-6) -45444123*a(n-7) [phone]*a(n-8) -63363708*a(n-9) [phone]*a(n-10) -18662400*a(n-11) for n>12