A204193 Number of nX4 0..1 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..1 introduced in row major order

5, 50, 86, 265, 883, 2974, 9940, 33462, 112470, 377908, 1270638, 4271547, 14358358, 48270403, 162269445, 545492694, 1833790077, 6164622703, 20723502506, 69666040146, 234195417025, 787291729779, 2646629705960, 8897142589375

Offset

1,1

Comments

Column 4 of A204197

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +7*a(n-2) +a(n-3) -28*a(n-4) -30*a(n-5) +56*a(n-6) +71*a(n-7) -64*a(n-8) -74*a(n-9) +42*a(n-10) +39*a(n-11) -18*a(n-12) -9*a(n-13) +6*a(n-14) +a(n-15) -a(n-16) for n>19

Example

Some solutions for n=5
..0..0..1..1....0..1..0..0....0..1..0..0....0..1..0..0....0..0..1..1
..0..1..0..0....0..1..0..0....1..0..1..1....1..1..0..1....0..1..0..0
..1..1..0..1....1..0..1..1....1..0..1..0....0..0..1..1....1..1..0..1
..1..0..1..1....0..0..1..0....0..1..0..0....1..1..0..0....1..0..1..0
..0..1..1..0....0..1..0..0....1..1..0..1....0..1..0..1....0..1..0..0

Crossrefs

Sequence in context: A169964 A061474 A136916 * A136919 A136920 A358686

Adjacent sequences: A204190 A204191 A204192 * A204194 A204195 A204196

Keyword

nonn

Author

R. H. Hardin Jan 12 2012

Status

approved