A300493 Number of nX3 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

4, 18, 52, 143, 412, 1225, 3699, 11243, 34012, 102446, 307967, 926094, 2787783, 8398551, 25307489, 76250370, 229695945, 691863018, 2083934202, 6277172983, 18908580942, 56958622146, 171576895601, 516838549210, 1556857505073

Offset

1,1

Comments

Column 3 of A300498.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -17*a(n-2) +12*a(n-3) +23*a(n-4) -46*a(n-5) +4*a(n-6) +24*a(n-7) +20*a(n-8) -52*a(n-9) +5*a(n-10) +53*a(n-11) +22*a(n-12) -47*a(n-13) -86*a(n-14) +78*a(n-15) +89*a(n-16) +84*a(n-17) -64*a(n-18) -22*a(n-19) -35*a(n-20) +15*a(n-21) +a(n-22) +4*a(n-23) -a(n-24) for n>25

Example

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

Crossrefs

Cf. A300498.

Sequence in context: A092349 A027659 A059133 * A300876 A301486 A284607

Adjacent sequences: A300490 A300491 A300492 * A300494 A300495 A300496

Keyword

nonn

Author

R. H. Hardin, Mar 07 2018

Status

approved