A317898 Number of nX4 0..1 arrays with every element unequal to 2, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 2, 3, 13, 31, 54, 116, 342, 956, 2459, 6366, 16404, 42964, 112558, 294354, 768840, 2007738, 5246415, 13708041, 35818742, 93591255, 244546559, 638982739, 1669591197, 4362471879, 11398715036, 29783832169, 77822515690, 203343065801

Offset

1,2

Comments

Column 4 of A317902.

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +3*a(n-3) +4*a(n-4) +12*a(n-5) +3*a(n-6) -3*a(n-7) -39*a(n-8) -52*a(n-9) -83*a(n-10) -74*a(n-11) -30*a(n-12) +123*a(n-13) +206*a(n-14) +254*a(n-15) +83*a(n-16) +26*a(n-17) -41*a(n-18) -47*a(n-19) -79*a(n-20) -34*a(n-21) -41*a(n-22) +11*a(n-23) -18*a(n-24) -3*a(n-25) +7*a(n-26) +5*a(n-27) -6*a(n-28) +4*a(n-29) -a(n-30) for n>34

Example

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

Crossrefs

Cf. A317902.

Sequence in context: A233523 A256712 A092175 * A317187 A296291 A072997

Adjacent sequences: A317895 A317896 A317897 * A317899 A317900 A317901

Keyword

nonn

Author

R. H. Hardin, Aug 10 2018

Status

approved