A303017 Number of 3 X n 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 25, 68, 187, 579, 1797, 5571, 17382, 54589, 171758, 541502, 1710237, 5408966, 17123725, 54254138, 172005475, 545590319, 1731242563, 5495164970, 17446421788, 55400350112, 175946894177, 558856114250, 1775239587936, 5639545671984, 17916569853876, 56922515406874

Offset

1,1

Comments

Row 3 of A303016.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -7*a(n-2) -11*a(n-3) +11*a(n-4) +a(n-5) +49*a(n-6) -12*a(n-7) -59*a(n-8) -61*a(n-9) +23*a(n-10) +89*a(n-11) +28*a(n-12) -24*a(n-13) -44*a(n-14) +12*a(n-15) for n>16.

Example

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

Crossrefs

Cf. A303016.

Sequence in context: A212893 A376483 A302324 * A281339 A298282 A077205

Adjacent sequences: A303014 A303015 A303016 * A303018 A303019 A303020

Keyword

nonn

Author

R. H. Hardin, Apr 17 2018

Status

approved