A301611 Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

2, 34, 367, 3816, 40085, 421025, 4422826, 46459647, 488047397, 5126802206, 53855652961, 565739028561, 5942934438842, 62428910463417, 655798724558441, 6888987247456952, 72366937453302201, 760194996499019669

Offset

1,1

Comments

Column 4 of A301615.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +41*a(n-2) -12*a(n-3) -318*a(n-4) -262*a(n-5) +724*a(n-6) +1034*a(n-7) -1340*a(n-8) -3422*a(n-9) +4016*a(n-10) +12158*a(n-11) +6925*a(n-12) -17989*a(n-13) -30269*a(n-14) +7574*a(n-15) +1694*a(n-16) +8004*a(n-17) -672*a(n-18) +432*a(n-19) -864*a(n-20) for n>21

Example

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

Crossrefs

Cf. A301615.

Sequence in context: A098531 A356342 A296995 * A224294 A092408 A180764

Adjacent sequences: A301608 A301609 A301610 * A301612 A301613 A301614

Keyword

nonn

Author

R. H. Hardin, Mar 24 2018

Status

approved