A274899 Number of 7 X n 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-1) or (-2,0) and new values introduced in order 0..2.

48, 95, 436, 2049, 9863, 48269, 237807, 1173787, 5803040, 28746995, 142599041, 707620370, 3511083299, 17420351674, 86438549422, 428942623935, 2128651136675, 10563418237405, 52420279346379, 260132938554538, 1290906088470552

Offset

1,1

Comments

Row 7 of A274895.

Links

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

Formula

Empirical: a(n) = 21*a(n-1) -209*a(n-2) +1330*a(n-3) -6059*a(n-4) +20839*a(n-5) -55739*a(n-6) +118287*a(n-7) -202495*a(n-8) +284119*a(n-9) -331806*a(n-10) +326718*a(n-11) -273224*a(n-12) +193798*a(n-13) -115270*a(n-14) +56258*a(n-15) -21837*a(n-16) +6481*a(n-17) -1404*a(n-18) +210*a(n-19) -20*a(n-20) +a(n-21) for n>22.

Example

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

Crossrefs

Cf. A274895.

Sequence in context: A260973 A260063 A211723 * A218486 A043418 A031486

Adjacent sequences: A274896 A274897 A274898 * A274900 A274901 A274902

Keyword

nonn

Author

R. H. Hardin, Jul 10 2016

Status

approved