A302410 Number of nX3 0..1 arrays with every element equal to 0, 1, 2 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 17, 30, 120, 441, 1431, 4754, 16423, 55848, 188797, 641401, 2181141, 7403533, 25137442, 85383840, 289971604, 984703839, 3344148948, 11357024856, 38568809117, 130981523021, 444820935270, 1510634631331, 5130191496078

Offset

1,1

Comments

Column 3 of A302415.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +2*a(n-2) +11*a(n-3) +a(n-4) -18*a(n-5) -14*a(n-6) -24*a(n-7) +52*a(n-8) -4*a(n-9) +8*a(n-10) -24*a(n-11) +24*a(n-12) -32*a(n-13)

Example

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

Crossrefs

Cf. A302415.

Sequence in context: A163736 A249582 A127547 * A303177 A212756 A031040

Adjacent sequences: A302407 A302408 A302409 * A302411 A302412 A302413

Keyword

nonn

Author

R. H. Hardin, Apr 07 2018

Status

approved