A300771 Number of nX3 0..1 arrays with every element equal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 2, 3, 11, 32, 102, 330, 1059, 3418, 11023, 35561, 114744, 370251, 1194696, 3854994, 12439181, 40138345, 129517277, 417922738, 1348541219, 4351434893, 14041088118, 45307389076, 146196612400, 471743129235, 1522207498886, 4911816468097

Offset

1,2

Comments

Column 3 of A300776.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +3*a(n-3) -3*a(n-4) +5*a(n-5) -2*a(n-6) -11*a(n-7) -13*a(n-8) +11*a(n-9) -2*a(n-10) -5*a(n-11) +a(n-12) +5*a(n-13) -4*a(n-14) +a(n-15)

Example

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

Crossrefs

Cf. A300776.

Sequence in context: A144056 A268687 A062630 * A296005 A374310 A159458

Adjacent sequences: A300768 A300769 A300770 * A300772 A300773 A300774

Keyword

nonn

Author

R. H. Hardin, Mar 12 2018

Status

approved