A303326 Number of 4 X n 0..1 arrays with every element equal to 0, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

8, 2, 8, 2, 12, 10, 46, 50, 204, 290, 1034, 1682, 5458, 9802, 29582, 57122, 163166, 332930, 911976, 1940450, 5149146, 11309770, 29300080, 65918162, 167721900, 384199202, 964447184, 2239277042, 5564863708, 13051463050, 32192084054

Offset

1,1

Comments

Row 4 of A303325.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +9*a(n-2) -16*a(n-3) -25*a(n-4) +34*a(n-5) +15*a(n-6) +4*a(n-7) +34*a(n-8) -64*a(n-9) -42*a(n-10) +20*a(n-11) -7*a(n-12) +34*a(n-13) +21*a(n-14) -8*a(n-15) -a(n-16) -6*a(n-17) -3*a(n-18) for n > 19.

Example

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

Crossrefs

Cf. A303325.

Sequence in context: A253721 A021551 A143025 * A085967 A163960 A246849

Adjacent sequences: A303323 A303324 A303325 * A303327 A303328 A303329

Keyword

nonn

Author

R. H. Hardin, Apr 21 2018

Status

approved