A252954 Number of (n+2)X(1+2) 0..4 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order

60, 140, 297, 711, 1543, 3461, 7637, 16689, 35609, 78429, 165847, 353699, 759497, 1602963, 3361709, 7188651, 14983771, 31325141, 66287453, 137719185, 285727121, 602441997, 1243951375, 2572947779, 5396750465, 11110939203, 22884164645

Offset

1,1

Comments

Column 1 of A252961

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -10*a(n-2) +10*a(n-3) -61*a(n-4) +124*a(n-5) +45*a(n-6) -182*a(n-7) -54*a(n-8) -570*a(n-9) +2205*a(n-10) -2268*a(n-11) +756*a(n-12) for n>15

Example

Some solutions for n=2
..0..1..1....0..1..1....0..1..0....0..1..1....0..1..0....0..0..1....0..1..1
..1..0..0....2..2..3....2..2..0....2..0..0....1..2..1....2..0..2....2..0..0
..2..3..2....4..4..0....3..0..0....3..2..2....3..3..2....3..0..3....3..2..2
..4..4..3....0..0..4....0..3..0....1..1..3....0..0..3....4..0..0....1..3..3

Crossrefs

Sequence in context: A334407 A336628 A336443 * A221990 A043478 A044311

Adjacent sequences: A252951 A252952 A252953 * A252955 A252956 A252957

Keyword

nonn

Author

R. H. Hardin, Dec 25 2014

Status

approved