login
A303103
Number of 3Xn 0..1 arrays with every element equal to 1, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
0, 11, 77, 431, 2913, 19393, 128921, 857789, 5706297, 37961366, 252538085, 1680012401, 11176296913, 74350419884, 494616846377, 3290443118074, 21889703025083, 145621450295042, 968748034460686, 6444605189965405
OFFSET
1,2
COMMENTS
Row 3 of A303102.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) +11*a(n-2) +a(n-4) -8*a(n-5) -a(n-6) -20*a(n-7) -2*a(n-8) -13*a(n-9) +3*a(n-10) -6*a(n-11) -5*a(n-12) +a(n-13) -2*a(n-14) for n>15
EXAMPLE
Some solutions for n=5
..0..1..1..1..1. .0..0..1..1..0. .0..0..1..1..1. .0..0..1..0..0
..1..0..1..0..0. .1..1..0..0..1. .0..0..0..1..0. .1..1..0..1..0
..0..0..0..1..1. .0..0..0..1..1. .0..1..1..0..1. .1..1..0..0..1
CROSSREFS
Cf. A303102.
Sequence in context: A059625 A355053 A023010 * A258459 A320547 A022639
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 18 2018
STATUS
approved