A232151 Number of 3Xn 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally, diagonally or antidiagonally

1, 145, 3669, 67725, 1345057, 27888353, 572956549, 11720173753, 239945876241, 4914834120181, 100662128740253, 2061578515560877, 42221864226950145, 864724020040862701, 17709947243340576177, 362707660633719422837

Offset

1,2

Comments

Row 3 of A232149

Links

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

Formula

Empirical: a(n) = 15*a(n-1) +68*a(n-2) +683*a(n-3) +4587*a(n-4) +1332*a(n-5) -32302*a(n-6) -47941*a(n-7) -49247*a(n-8) -33578*a(n-9) +48420*a(n-10) +25707*a(n-11) +23404*a(n-12) +22761*a(n-13) +1376*a(n-14) +2938*a(n-15) -66*a(n-16) -640*a(n-17) +368*a(n-18) -240*a(n-19)

Example

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

Crossrefs

Sequence in context: A365204 A269015 A234116 * A264284 A008377 A076464

Adjacent sequences: A232148 A232149 A232150 * A232152 A232153 A232154

Keyword

nonn

Author

R. H. Hardin, Nov 19 2013

Status

approved