A300876 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

4, 18, 52, 148, 440, 1367, 4297, 13510, 42216, 131239, 407238, 1264321, 3929780, 12224311, 38033755, 118318333, 367999398, 1144440136, 3559039439, 11068454635, 34423573923, 107061087524, 332971544913, 1035570611253, 3220697791617

Offset

1,1

Comments

Column 3 of A300881.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -15*a(n-2) +44*a(n-4) -42*a(n-5) -42*a(n-6) +45*a(n-7) +44*a(n-8) -3*a(n-9) -15*a(n-10) -49*a(n-11) -52*a(n-12) -26*a(n-13) +86*a(n-14) +194*a(n-15) +84*a(n-16) +42*a(n-17) -92*a(n-18) -76*a(n-19) -43*a(n-20) -a(n-21) +13*a(n-22) +4*a(n-23) +3*a(n-24) -a(n-25) for n>26

Example

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

Crossrefs

Cf. A300881.

Sequence in context: A027659 A059133 A300493 * A301486 A284607 A297945

Adjacent sequences: A300873 A300874 A300875 * A300877 A300878 A300879

Keyword

nonn

Author

R. H. Hardin, Mar 14 2018

Status

approved