A317738 Number of nX5 0..1 arrays with every element unequal to 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 4, 2, 14, 14, 38, 74, 149, 269, 662, 1294, 2721, 5911, 12084, 25175, 53473, 111383, 233690, 490578, 1030868, 2158490, 4533365, 9504248, 19950172, 41823355, 87810137, 184117052, 386450223, 810444428, 1700925286, 3567310635, 7486285033

Offset

1,2

Comments

Column 5 of A317741.

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +5*a(n-3) +5*a(n-4) -6*a(n-5) -a(n-6) -15*a(n-7) +16*a(n-8) -23*a(n-9) +4*a(n-10) -82*a(n-11) -46*a(n-12) -44*a(n-13) +101*a(n-14) +160*a(n-15) +83*a(n-16) +21*a(n-17) -52*a(n-18) +83*a(n-19) +154*a(n-20) +284*a(n-21) +155*a(n-22) -76*a(n-23) -161*a(n-24) -125*a(n-25) -49*a(n-26) -3*a(n-27) +40*a(n-28) +11*a(n-29) -5*a(n-30) -2*a(n-31) -2*a(n-32) +a(n-33) for n>39

Example

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

Crossrefs

Cf. A317741.

Sequence in context: A248249 A161134 A184183 * A224893 A087957 A360084

Adjacent sequences: A317735 A317736 A317737 * A317739 A317740 A317741

Keyword

nonn

Author

R. H. Hardin, Aug 05 2018

Status

approved