A222094 Number of 2 X n arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns.

3, 31, 306, 3014, 29671, 292017, 2873693, 28278630, 278273755, 2738325414, 26946205188, 265161285275, 2609291560659, 25676457366269, 252666460567318, 2486337558528381, 24466541550530492, 240760412205806134

Offset

1,1

Comments

Row 2 of A222093.

Links

R. H. Hardin, Table of n, a(n) for n = 1..170

Formula

Empirical: a(n) = 17*a(n-1) - 90*a(n-2) + 217*a(n-3) - 258*a(n-4) + 156*a(n-5) - 44*a(n-6) + 4*a(n-7).

Empirical g.f.: x*(3 - 20*x + 49*x^2 - 49*x^3 + 20*x^4 - 2*x^5) / (1 - 17*x + 90*x^2 - 217*x^3 + 258*x^4 - 156*x^5 + 44*x^6 - 4*x^7). - Colin Barker, Aug 15 2018

Example

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

Crossrefs

Cf. A222093.

Sequence in context: A144579 A348709 A220997 * A069589 A222090 A037778

Adjacent sequences: A222091 A222092 A222093 * A222095 A222096 A222097

Keyword

nonn

Author

R. H. Hardin, Feb 07 2013

Status

approved