A281059 Number of 4Xn 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 29, 376, 1022, 2452, 5400, 10570, 19892, 36616, 66354, 118926, 211382, 373266, 655580, 1146156, 1995858, 3463242, 5990498, 10332426, 17775144, 30506480, 52242450, 89285638, 152311246, 259377954, 440998484, 748670868, 1269219570

Offset

1,2

Comments

Row 4 of A281056.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -12*a(n-2) +5*a(n-3) +12*a(n-4) -12*a(n-5) -3*a(n-6) +6*a(n-7) -a(n-9) for n>17

Example

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

Crossrefs

Cf. A281056.

Sequence in context: A234810 A077516 A142278 * A010834 A022721 A125441

Adjacent sequences: A281056 A281057 A281058 * A281060 A281061 A281062

Keyword

nonn

Author

R. H. Hardin, Jan 13 2017

Status

approved