A241074 Number of nX3 0..2 arrays with no element equal to exactly one horizontal or vertical neighbor, with new values 0..2 introduced in row major order

2, 12, 67, 386, 2333, 14438, 90729, 576616, 3692697, 23768052, 153496623, 993485284, 6439467991, 41777922610, 271212402395, 1761347749066, 11441763716997, 74338495106470, 483038660675361, 3138923546597920

Offset

1,1

Comments

Column 3 of A241078

Links

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

Formula

Empirical: a(n) = 13*a(n-1) -53*a(n-2) +90*a(n-3) -196*a(n-4) +404*a(n-5) +124*a(n-6) +242*a(n-7) -955*a(n-8) -3141*a(n-9) -2695*a(n-10) +1876*a(n-11) +9112*a(n-12) +7732*a(n-13) +8168*a(n-14) -12592*a(n-15) -17664*a(n-16) -3904*a(n-17) +11648*a(n-18) +4864*a(n-19) -3072*a(n-20) for n>21

Example

Some solutions for n=4
..0..1..2....0..1..2....0..1..2....0..0..1....0..1..0....0..1..0....0..0..0
..2..0..1....1..0..1....1..2..0....0..0..0....2..0..2....1..2..1....0..1..0
..1..1..2....0..1..0....0..1..2....1..0..0....0..1..0....0..0..0....0..0..0
..1..1..0....1..0..2....1..0..1....2..1..2....1..0..2....0..0..0....2..0..0

Crossrefs

Sequence in context: A180195 A377507 A212389 * A020062 A185035 A185235

Adjacent sequences: A241071 A241072 A241073 * A241075 A241076 A241077

Keyword

nonn

Author

R. H. Hardin, Apr 15 2014

Status

approved