A279921 Number of nX2 0..2 arrays with no element equal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

1, 0, 15, 142, 1350, 12858, 119396, 1095012, 9924024, 89076240, 792954264, 7008783648, 61565762448, 537846507200, 4675888234720, 40474106338144, 348966901404864, 2998086166443584, 25674017271458048, 219205885504644096

Offset

1,3

Comments

Column 2 of A279925.

Links

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

Formula

Empirical: a(n) = 24*a(n-1) -192*a(n-2) +500*a(n-3) +204*a(n-4) -996*a(n-5) +1248*a(n-6) -1056*a(n-7) -4176*a(n-8) +2528*a(n-9) +912*a(n-10) -1536*a(n-11) +8896*a(n-12) +5376*a(n-13) -3648*a(n-14) -192*a(n-15) -3840*a(n-16) -9216*a(n-17) -4096*a(n-18) for n>19

Example

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

Crossrefs

Cf. A279925.

Sequence in context: A045724 A241402 A252825 * A179524 A235864 A177065

Adjacent sequences: A279918 A279919 A279920 * A279922 A279923 A279924

Keyword

nonn

Author

R. H. Hardin, Dec 23 2016

Status

approved