A302311 Number of 3 X n 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 6, 13, 26, 48, 121, 275, 600, 1296, 2998, 6731, 15022, 33412, 75480, 169232, 379265, 848913, 1907065, 4276079, 9589159, 21494910, 48224727, 108142434, 242526545, 543834226, 1219737296, 2735350513, 6134430103, 13756843652, 30852213480

Offset

1,1

Comments

Row 3 of A302309.

Links

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) -a(n-3) +8*a(n-4) -7*a(n-5) -22*a(n-6) +9*a(n-7) -14*a(n-8) +10*a(n-9) +39*a(n-10) -19*a(n-11) +6*a(n-12) -18*a(n-14) +9*a(n-15) for n>16.

Example

Some solutions for n=5
..0..1..0..1..0. .0..0..1..0..1. .0..0..1..0..1. .0..1..1..1..0
..0..1..0..1..1. .0..1..0..0..1. .1..1..1..0..0. .0..1..0..1..0
..0..1..0..1..0. .0..1..0..1..0. .0..0..1..0..1. .0..1..0..0..0

Crossrefs

Cf. A302309.

Sequence in context: A262194 A136391 A105205 * A160805 A359020 A246424

Adjacent sequences: A302308 A302309 A302310 * A302312 A302313 A302314

Keyword

nonn

Author

R. H. Hardin, Apr 05 2018

Status

approved