A197053 Number of nX7 0..4 arrays with each element equal to the number its horizontal and vertical zero neighbors.

7, 26, 156, 692, 3580, 17742, 88056, 439338, 2192602, 10912392, 54394628, 271160024, 1351103246, 6733077562, 33557756016, 167232569172, 833404135538, 4153405692526, 20698773896328, 103153449929238, 514074952403758

Offset: 1

Author

R. H. Hardin Oct 09 2011

Keywords

• nonn

Comments

Every 0 is next to 0 0's, every 1 is next to 1 0's, every 2 is next to 2 0's, every 3 is next to 3 0's, every 4 is next to 4 0's

Column 7 of A197054

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-1) +9*a(n-2) +37*a(n-3) -187*a(n-5) -77*a(n-6) +248*a(n-7) +240*a(n-8) -1400*a(n-9) +564*a(n-10) +1220*a(n-11) +1358*a(n-12) -5000*a(n-13) +3019*a(n-14) +1209*a(n-15) +4104*a(n-16) -6840*a(n-17) +3995*a(n-18) +4214*a(n-19) -1497*a(n-20) -1140*a(n-21) -945*a(n-22) +1251*a(n-23) -2502*a(n-24) -60*a(n-25) -49*a(n-26) -272*a(n-27) +281*a(n-28) -376*a(n-29) -109*a(n-30) +103*a(n-31) +9*a(n-32) -27*a(n-33) -3*a(n-34) +6*a(n-35)