A303178 Number of nX4 0..1 arrays with every element equal to 0, 1, 2, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

8, 37, 72, 297, 1302, 5050, 20188, 81926, 329957, 1329466, 5358347, 21608578, 87101482, 351134917, 1415564660, 5706662796, 23005513674, 92743499633, 373882345405, 1507253219678, 6076276040079, 24495641982958, 98750689289605

Offset

1,1

Comments

Column 4 of A303182.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +6*a(n-2) -a(n-3) -15*a(n-4) -47*a(n-5) -18*a(n-6) +91*a(n-7) +121*a(n-8) +35*a(n-9) -33*a(n-10) -205*a(n-11) -172*a(n-12) -49*a(n-13) +107*a(n-14) +182*a(n-15) -26*a(n-16) +178*a(n-17) +171*a(n-18) -156*a(n-19) -88*a(n-20) -98*a(n-21) -154*a(n-22) +74*a(n-23) +127*a(n-24) +19*a(n-25) -63*a(n-26) -13*a(n-27) +26*a(n-28) -a(n-29) +4*a(n-30) -4*a(n-31) for n>33

Example

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

Crossrefs

Cf. A303182.

Sequence in context: A281465 A302619 A302411 * A250168 A244870 A309281

Adjacent sequences: A303175 A303176 A303177 * A303179 A303180 A303181

Keyword

nonn

Author

R. H. Hardin, Apr 19 2018

Status

approved