A280175 Number of nX3 0..1 arrays with no element unequal 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.

0, 12, 60, 279, 1082, 3931, 13720, 46467, 153650, 499289, 1598693, 5059881, 15855622, 49273183, 152010000, 466006394, 1420614227, 4309242893, 13013193556, 39139655092, 117289714264, 350310455965, 1043078536630, 3097120192877

Offset

1,2

Comments

Column 3 of A280180.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -24*a(n-2) -9*a(n-3) +147*a(n-4) -213*a(n-5) -80*a(n-6) +567*a(n-7) -624*a(n-8) -30*a(n-9) +711*a(n-10) -687*a(n-11) +215*a(n-12) +84*a(n-13) +3*a(n-14) -86*a(n-15) +27*a(n-16) +6*a(n-17) -17*a(n-18) -18*a(n-19) -6*a(n-20) -a(n-21) for n>28

Example

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

Crossrefs

Cf. A280180.

Sequence in context: A086950 A370700 A074433 * A216491 A114307 A009031

Adjacent sequences: A280172 A280173 A280174 * A280176 A280177 A280178

Keyword

nonn

Author

R. H. Hardin, Dec 28 2016

Status

approved