A281061 Number of 6Xn 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, 468, 4988, 10112, 22106, 46610, 87995, 159317, 282552, 495655, 864369, 1501627, 2601791, 4498333, 7762266, 13369326, 22983871, 39440039, 67556367, 115513187, 197179026, 336035590, 571793109, 971529387, 1648428839, 2793279473

Offset

1,2

Comments

Row 6 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>19

Example

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

Crossrefs

Cf. A281056.

Sequence in context: A205415 A205408 A282116 * A270259 A205407 A045305

Adjacent sequences: A281058 A281059 A281060 * A281062 A281063 A281064

Keyword

nonn

Author

R. H. Hardin, Jan 13 2017

Status

approved