login
A302742
Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
4, 32, 228, 1637, 11814, 85268, 615589, 4444226, 32085336, 231641898, 1672352613, 12073650477, 87166448968, 629303444781, 4543294244531, 32800587324576, 236805822155030, 1709633941974433, 12342805548255732, 89109630466361141
OFFSET
1,1
COMMENTS
Row 3 of A302741.
LINKS
FORMULA
Empirical: a(n) = 7*a(n-1) +4*a(n-2) -17*a(n-3) -3*a(n-4) -9*a(n-6) +14*a(n-7) for n>8
EXAMPLE
Some solutions for n=5
..0..0..1..0..1. .0..0..1..1..0. .0..1..0..1..0. .0..1..0..0..1
..1..1..0..1..1. .1..0..0..1..0. .1..0..0..0..1. .0..1..0..1..0
..0..1..1..0..0. .0..1..1..0..1. .1..1..0..0..1. .1..1..1..0..1
CROSSREFS
Cf. A302741.
Sequence in context: A125823 A320366 A317560 * A300210 A302736 A033515
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 12 2018
STATUS
approved