A198649 Number of n X 2 0..6 arrays with values 0..6 introduced in row major order and each element equal to at least one horizontal or vertical neighbor.

1, 3, 14, 76, 488, 3521, 28030, 242849, 2264711, 22514016, 236355581, 2595953878, 29564752028, 346348460016, 4145325240330, 50411121219126, 620250713489362, 7696399884065815, 96085558605681094, 1204839099133770019

Offset

1,2

Comments

Column 2 of A198654.

Links

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

Formula

Empirical: a(n)=37*a(n-1)-502*a(n-2)+2817*a(n-3)-2399*a(n-4)-35852*a(n-5)+95494*a(n-6)+127482*a(n-7)-450424*a(n-8)-527274*a(n-9)+944990*a(n-10)+1784424*a(n-11)-456873*a(n-12)-2779579*a(n-13)-1492318*a(n-14)+1457417*a(n-15)+1939617*a(n-16)+390628*a(n-17)-559484*a(n-18)-375300*a(n-19)-62900*a(n-20).

Example

Some solutions with all values 0 to 6 for n=7
..0..0....0..0....0..1....0..0....0..0....0..0....0..0....0..1....0..1....0..1
..1..1....1..1....0..1....1..1....1..1....1..1....1..2....0..1....0..1....0..1
..2..2....2..2....2..3....2..2....2..3....2..2....1..2....2..2....2..2....2..2
..3..4....3..3....2..3....3..4....2..3....3..3....3..3....3..4....3..3....3..4
..3..4....4..4....4..4....3..4....4..4....4..5....4..4....3..4....4..4....3..4
..5..6....5..6....5..6....5..5....5..5....4..5....5..5....5..6....5..6....5..5
..5..6....5..6....5..6....6..6....6..6....6..6....6..6....5..6....5..6....6..6

Crossrefs

Cf. A198654.

Sequence in context: A353253 A198702 A198621 * A198656 A240402 A048779

Adjacent sequences: A198646 A198647 A198648 * A198650 A198651 A198652

Keyword

nonn

Author

R. H. Hardin, Oct 28 2011

Status

approved