A302473 Number of 3Xn 0..1 arrays with every element equal to 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

0, 11, 49, 203, 955, 4556, 21843, 103319, 491073, 2332753, 11082938, 52648987, 250106679, 1188163911, 5644397853, 26814116700, 127381683511, 605134192403, 2874722191055, 13656526930929, 64876076932622, 308197362006435

Offset

1,2

Comments

Row 3 of A302472.

Links

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

Formula

Empirical: a(n) = a(n-1) +17*a(n-2) +15*a(n-3) -33*a(n-4) -62*a(n-5) -148*a(n-6) -116*a(n-7) +343*a(n-8) +429*a(n-9) +269*a(n-10) +191*a(n-11) -415*a(n-12) -534*a(n-13) -468*a(n-14) -436*a(n-15) -132*a(n-16) -72*a(n-17) -8*a(n-18) +8*a(n-19) for n>21

Example

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

Crossrefs

Cf. A302472.

Sequence in context: A295420 A003063 A124857 * A126398 A159486 A284857

Adjacent sequences: A302470 A302471 A302472 * A302474 A302475 A302476

Keyword

nonn

Author

R. H. Hardin, Apr 08 2018

Status

approved