A326160 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

3, 6, 9, 25, 60, 160, 396, 996, 2480, 6213, 15537, 38935, 97574, 244521, 612350, 1533665, 3841552, 9623474, 24106566, 60386058, 151263372, 378906980, 949140173, 2377551381, 5955661956, 14918670478, 37370561312, 93611479464, 234492365157

Offset

1,1

Comments

Column 3 of A326165.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -5*a(n-2) -13*a(n-3) +38*a(n-4) -31*a(n-5) -41*a(n-6) +136*a(n-7) -125*a(n-8) -80*a(n-9) +370*a(n-10) -296*a(n-11) -270*a(n-12) +562*a(n-13) -178*a(n-14) -302*a(n-15) +321*a(n-16) -43*a(n-17) -63*a(n-18) +71*a(n-19) -103*a(n-20) +26*a(n-21) +54*a(n-22) -41*a(n-23) -a(n-24) +15*a(n-25) -5*a(n-26) -2*a(n-27) +a(n-28) for n>30

Example

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

Crossrefs

Cf. A326165.

Sequence in context: A061929 A358403 A318032 * A301536 A296110 A019461

Adjacent sequences: A326157 A326158 A326159 * A326161 A326162 A326163

Keyword

nonn

Author

R. H. Hardin, Jun 09 2019

Status

approved