A204147 Number of (n+2) X 4 0..2 arrays with every 3 X 3 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.

3902, 28982, 156494, 891662, 5117114, 29610374, 169527242, 970408838, 5556457154, 31877275262, 182767466954, 1047729630038, 6004794957602, 34422401233838, 197325074405594, 1131174528105062, 6484208526471314

Offset

1,1

Comments

Column 2 of A204153.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +9*a(n-2) -16*a(n-3) +162*a(n-4) -70*a(n-5) -704*a(n-6) -1224*a(n-7) -576*a(n-8) +4240*a(n-9) +11456*a(n-10) -6560*a(n-11) -14144*a(n-12) +5376*a(n-13) -7168*a(n-14) +13312*a(n-15) -4096*a(n-16) for n>17.

Example

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

Crossrefs

Cf. A204153.

Sequence in context: A247691 A242873 A135202 * A252138 A115468 A066386

Adjacent sequences: A204144 A204145 A204146 * A204148 A204149 A204150

Keyword

nonn

Author

R. H. Hardin, Jan 11 2012

Status

approved