A296331 Number of nX4 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 0 or 2 neighboring 1s.

8, 47, 230, 1235, 6504, 34224, 180404, 950451, 5007796, 26385348, 139020417, 732477787, 3859315404, 20334154462, 107137610499, 564492004530, 2974223725585, 15670738828479, 82566773061608, 435031946402290

Offset

1,1

Comments

Column 4 of A296335.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +4*a(n-2) +16*a(n-3) -4*a(n-4) -14*a(n-5) -72*a(n-6) -54*a(n-7) -102*a(n-8) +15*a(n-9) -113*a(n-10) +86*a(n-11) -184*a(n-12) +203*a(n-13) -255*a(n-14) +221*a(n-15) -177*a(n-16) +106*a(n-17) -55*a(n-18) +21*a(n-19) -6*a(n-20) +a(n-21)

Example

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

Crossrefs

Cf. A296335.

Sequence in context: A160640 A230622 A026983 * A081279 A099110 A106393

Adjacent sequences: A296328 A296329 A296330 * A296332 A296333 A296334

Keyword

nonn

Author

R. H. Hardin, Dec 10 2017

Status

approved