A231539 Number of nX3 0..1 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors

4, 20, 116, 589, 3001, 15644, 81179, 420243, 2177937, 11287977, 58494710, 303132340, 1570918959, 8140881877, 42188034539, 218628945511, 1132989453013, 5871432030067, 30427217632524, 157681390442587, 817144077007238

Offset

1,1

Comments

Column 3 of A231544

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -14*a(n-2) +34*a(n-3) -67*a(n-4) +86*a(n-5) -79*a(n-6) +14*a(n-7) +47*a(n-8) -66*a(n-9) +15*a(n-10) -105*a(n-11) +121*a(n-12) +24*a(n-13) -40*a(n-14) -56*a(n-15) +2*a(n-16) +43*a(n-17) -11*a(n-18) -15*a(n-19) -6*a(n-20) +2*a(n-21) +a(n-22)

Example

Some solutions for n=7
..1..0..0....1..1..0....1..1..1....1..0..0....0..0..0....1..0..1....1..0..0
..0..1..0....1..0..0....1..0..0....1..0..0....0..0..0....0..0..1....1..0..0
..0..0..0....0..0..1....0..0..0....0..1..1....0..0..1....1..0..0....0..0..1
..1..0..1....0..0..0....1..0..1....0..0..0....1..0..0....0..1..0....0..0..0
..0..1..0....0..0..0....0..0..0....0..0..1....0..0..1....0..0..0....0..0..0
..0..0..0....0..1..0....0..0..0....0..1..0....0..0..1....0..0..0....0..0..0
..0..1..1....1..0..0....1..1..0....0..0..0....0..0..0....1..1..1....1..0..0

Crossrefs

Sequence in context: A341919 A192924 A258664 * A106567 A077445 A085458

Adjacent sequences: A231536 A231537 A231538 * A231540 A231541 A231542

Keyword

nonn

Author

R. H. Hardin, Nov 10 2013

Status

approved