A281076 Number of nX4 0..1 arrays with no element equal to more than two of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

0, 24, 244, 958, 3330, 10474, 30808, 86860, 237624, 636256, 1676876, 4366076, 11259114, 28808224, 73230526, 185121918, 465742070, 1166862594, 2912703062, 7246920604, 17978001450, 44482281206, 109799225938, 270440705450

Offset

1,2

Comments

Column 4 of A281080.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -17*a(n-2) +15*a(n-3) -a(n-4) +3*a(n-5) -13*a(n-6) -3*a(n-7) +25*a(n-8) -13*a(n-9) -11*a(n-10) +5*a(n-11) +9*a(n-12) +a(n-13) -12*a(n-14) +4*a(n-15) +6*a(n-16) -4*a(n-17) -a(n-18) +a(n-19) for n>25

Example

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

Crossrefs

Cf. A281080.

Sequence in context: A267060 A086603 A304835 * A300397 A211148 A296648

Adjacent sequences: A281073 A281074 A281075 * A281077 A281078 A281079

Keyword

nonn

Author

R. H. Hardin, Jan 14 2017

Status

approved