A197312 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,1,1,0,0 for x=0,1,2,3,4.

2, 3, 5, 10, 128, 79, 249, 662, 2767, 3969, 14343, 26565, 85744, 172877, 540761, 1086259, 3216870, 6970421, 19943621, 43866426, 122208464, 276719535, 753092637, 1739409216, 4652758432, 10905015671, 28759884710, 68307698666, 178118628885

Offset: 1

Author

R. H. Hardin Oct 13 2011

Keywords

• nonn

Comments

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

Column 3 of A197317

Examples

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

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +3*a(n-3) +17*a(n-4) +a(n-5) +32*a(n-6) -13*a(n-7) -61*a(n-8) -41*a(n-9) -115*a(n-10) -83*a(n-11) -315*a(n-12) -280*a(n-13) -12*a(n-14) +214*a(n-15) -659*a(n-16) +358*a(n-17) +319*a(n-18) +247*a(n-19) -121*a(n-20) -109*a(n-21) -12*a(n-22) +50*a(n-23) +46*a(n-24) +a(n-25) -a(n-26) -3*a(n-27) for n>28