A302815 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 20, 75, 389, 1852, 8485, 41247, 196946, 931243, 4464289, 21314416, 101500589, 484945365, 2314846870, 11042132315, 52714123333, 251602109008, 1200668947009, 5730793024341, 27351896253430, 130538870872807, 623034403841625

Offset

1,1

Comments

Column 3 of A302820.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +5*a(n-2) +36*a(n-3) -62*a(n-4) -116*a(n-5) -142*a(n-6) -78*a(n-7) +150*a(n-8) -100*a(n-9) +176*a(n-10) +272*a(n-11) +320*a(n-12) -256*a(n-14)

Example

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

Crossrefs

Cf. A302820.

Sequence in context: A329174 A057333 A196432 * A196508 A121257 A145563

Adjacent sequences: A302812 A302813 A302814 * A302816 A302817 A302818

Keyword

nonn

Author

R. H. Hardin, Apr 13 2018

Status

approved