login
A295938
Number of n X 3 0..1 arrays with each 1 adjacent to 1 or 3 king-move neighboring 1's.
1
3, 15, 41, 120, 465, 1472, 4667, 16230, 53266, 173851, 584543, 1934414, 6378634, 21232506, 70378723, 232896476, 772967540, 2562676394, 8490559710, 28155930393, 93345299815, 309390211243, 1025742299033, 3400526966741, 11272379148340
OFFSET
1,1
COMMENTS
Column 3 of A295943.
FORMULA
Empirical: a(n) = a(n-1) + 3*a(n-2) + 18*a(n-3) + a(n-4) - 19*a(n-5) - 36*a(n-6) - 13*a(n-7) + 5*a(n-8) + 10*a(n-9).
Empirical formula confirmed by Robert Israel, Nov 30 2017 (see link).
EXAMPLE
Some solutions for n=7:
1 1 0 1 1 0 0 0 1 1 0 1 1 1 0 0 1 0 0 0 0
0 0 0 0 0 0 0 1 0 0 1 0 1 1 0 1 0 0 1 0 0
0 0 1 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1
0 1 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 1 0 0
0 0 0 0 0 1 0 0 1 1 0 1 0 1 0 0 0 1 0 0 0
0 1 0 1 1 0 0 0 0 1 0 1 1 0 1 0 0 1 1 1 0
0 0 1 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 0
CROSSREFS
Cf. A295943.
Sequence in context: A298655 A299608 A249835 * A096742 A012256 A012222
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 30 2017
STATUS
approved