A208874 Number of 3Xn 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors

5, 143, 6520, 307165, 14493405, 683903931, 32271626438, 1522813452263, 71857577327143, 3390770839381669, 160001593732718856, 7550056082308516761, 356267369073405009281, 16811323900505484274607, 793282337427660173475274

Offset

1,1

Comments

Row 3 of A208872

Links

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

Formula

Empirical: a(n) = 61*a(n-1) -722*a(n-2) +3476*a(n-3) -7851*a(n-4) +8583*a(n-5) -4266*a(n-6) +720*a(n-7) for n>8

Example

Some solutions for n=4
..0..1..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..2..2..1..2....1..1..1..2....1..2..2..1....1..1..1..0....1..1..1..0
..1..2..3..2....2..0..1..3....1..0..1..2....0..0..1..1....2..2..3..2

Crossrefs

Sequence in context: A066264 A171776 A277401 * A222289 A134503 A282836

Adjacent sequences: A208871 A208872 A208873 * A208875 A208876 A208877

Keyword

nonn

Author

R. H. Hardin Mar 02 2012

Status

approved