A318032 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

3, 6, 9, 25, 58, 152, 368, 904, 2211, 5420, 13257, 32485, 79687, 195459, 479166, 1174486, 2879048, 7057869, 17302114, 42416167, 103983959, 254916060, 624918591, 1531968302, 3755586548, 9206752113, 22570177681, 55330344496, 135641228111

Offset

1,1

Comments

Column 3 of A318037.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -9*a(n-2) +7*a(n-3) +6*a(n-4) -27*a(n-5) +37*a(n-6) -22*a(n-7) -23*a(n-8) +31*a(n-9) +9*a(n-10) -29*a(n-11) +48*a(n-12) -27*a(n-13) +25*a(n-14) -8*a(n-15) -24*a(n-16) +28*a(n-17) -60*a(n-18) +60*a(n-19) -63*a(n-20) +49*a(n-21) -39*a(n-22) +25*a(n-23) -13*a(n-24) +4*a(n-25) +2*a(n-26) -3*a(n-27) +4*a(n-28) -a(n-29) +a(n-30) for n>33

Example

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

Crossrefs

Cf. A318037.

Sequence in context: A026095 A061929 A358403 * A326160 A301536 A296110

Adjacent sequences: A318029 A318030 A318031 * A318033 A318034 A318035

Keyword

nonn

Author

R. H. Hardin, Aug 13 2018

Status

approved