A301493 Number of nX3 0..1 arrays with every element equal to 0, 1, 3, 4, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

3, 2, 5, 15, 45, 156, 479, 1455, 4493, 14037, 43495, 134587, 417047, 1293362, 4008799, 12423540, 38505876, 119353345, 369934949, 1146596091, 3553853570, 11015153343, 34141324269, 105820474738, 327989056256, 1016597761211, 3150930739290

Offset

1,1

Comments

Column 3 of A301498.

Links

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

Formula

Empirical: a(n) = a(n-1) +5*a(n-2) +5*a(n-3) +12*a(n-4) -13*a(n-5) -66*a(n-6) -64*a(n-7) -34*a(n-8) +72*a(n-9) +226*a(n-10) +194*a(n-11) -29*a(n-12) -203*a(n-13) -99*a(n-14) +87*a(n-15) +78*a(n-16) -9*a(n-17) -24*a(n-18) -6*a(n-19) for n>23

Example

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

Crossrefs

Cf. A301498.

Sequence in context: A068553 A174909 A187943 * A214502 A077039 A374834

Adjacent sequences: A301490 A301491 A301492 * A301494 A301495 A301496

Keyword

nonn

Author

R. H. Hardin, Mar 22 2018

Status

approved