A198448 Number of 2nX4 0..2 arrays with values 0..2 introduced in row major order and each element unequal to exactly two horizontal and vertical neighbors

13, 177, 1399, 14109, 146187, 1532249, 16411255, 176845253, 1916108803, 20825391089, 226732488271, 2471217945565, 26951222470875, 294040889182217, 3208725606852775, 35019790320698997, 382232607221676979

Offset

1,1

Comments

Column 2 of A198452

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 20*a(n-1) -94*a(n-2) -208*a(n-3) +1351*a(n-4) +5600*a(n-5) -22336*a(n-6) -39628*a(n-7) +116496*a(n-8) +216496*a(n-9) -188416*a(n-10) -809920*a(n-11) -267264*a(n-12) +1638400*a(n-13)

Example

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

Crossrefs

Sequence in context: A295507 A109392 A297691 * A349247 A331496 A196435

Adjacent sequences: A198445 A198446 A198447 * A198449 A198450 A198451

Keyword

nonn

Author

R. H. Hardin Oct 25 2011

Status

approved