A281535 Number of nX3 0..2 arrays with no element equal to more than one of its king-move neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 4, 290, 2919, 14561, 63840, 245037, 871492, 2953605, 9666482, 30769771, 95835530, 293254847, 884195974, 2632901317, 7756881944, 22642414159, 65560614848, 188478504627, 538421898582, 1529377862437, 4321992091946

Offset

1,2

Comments

Column 3 of A281540.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -6*a(n-2) +8*a(n-3) -31*a(n-4) +9*a(n-5) +6*a(n-6) +36*a(n-7) +87*a(n-8) -5*a(n-9) +106*a(n-10) -12*a(n-11) -13*a(n-12) +11*a(n-13) -102*a(n-14) +60*a(n-15) -42*a(n-16) -36*a(n-17) +68*a(n-18) -28*a(n-19) +16*a(n-21) -8*a(n-22) for n>30

Example

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

Crossrefs

Cf. A281540.

Sequence in context: A221135 A110816 A112322 * A110071 A256703 A176432

Adjacent sequences: A281532 A281533 A281534 * A281536 A281537 A281538

Keyword

nonn

Author

R. H. Hardin, Jan 23 2017

Status

approved