A296124 Number of n X 4 0..1 arrays with each 1 adjacent to 2 or 5 king-move neighboring 1s.

1, 13, 30, 74, 287, 841, 2463, 7953, 24428, 74660, 233017, 721069, 2226921, 6907921, 21399342, 66252970, 205308499, 636102161, 1970540971, 6105562057, 18917255184, 58610713832, 181598709121, 562663895105, 1743342282089, 5401567886229

Offset

1,2

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + a(n-2) + 5*a(n-3) - 18*a(n-4) - 14*a(n-5) + 3*a(n-6) + a(n-7) + a(n-8) - a(n-9).

Empirical g.f.: x*(1 + x)*(1 + 9*x - 19*x^2 - 15*x^3 + 3*x^4 + x^5 + x^6 - x^7) / (1 - 3*x - x^2 - 5*x^3 + 18*x^4 + 14*x^5 - 3*x^6 - x^7 - x^8 + x^9). - Colin Barker, Feb 22 2019

Example

Some solutions for n=7:
..0..1..0..0. .0..0..1..1. .0..0..0..0. .0..0..1..1. .0..0..1..0
..1..0..1..0. .0..0..1..0. .0..0..0..0. .0..0..1..0. .1..1..1..0
..1..0..0..1. .0..0..0..0. .0..0..1..0. .0..0..0..0. .0..1..1..1
..1..0..1..0. .0..0..0..1. .0..1..1..0. .0..1..1..0. .0..1..0..0
..1..0..0..1. .0..0..1..1. .0..0..0..0. .1..0..0..1. .0..0..0..1
..0..1..1..0. .1..0..0..0. .1..0..0..0. .1..0..0..1. .0..0..1..1
..0..0..0..0. .1..1..0..0. .1..1..0..0. .0..1..1..0. .0..0..0..0

Crossrefs

Column 4 of A296128.

Sequence in context: A172463 A329950 A183445 * A299130 A156532 A227435

Adjacent sequences: A296121 A296122 A296123 * A296125 A296126 A296127

Keyword

nonn

Author

R. H. Hardin, Dec 05 2017

Status

approved