login
A263367
Number of (n+1)X(2+1) 0..2 arrays with each row and column divisible by 7, read as a base-3 number with top and left being the most significant digits.
1
1, 2, 7, 29, 112, 367, 1359, 5370, 21447, 86013, 343936, 1371301, 5479081, 21913562, 87653287, 350634149, 1402534912, 5609859607, 22439049159, 89756056050, 359024196327, 1436098422693, 5744393762896, 22977556193101, 91910198451361
OFFSET
1,2
COMMENTS
Column 2 of A263373.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +101*a(n-6) -404*a(n-7) -2159*a(n-12) +8636*a(n-13) +2059*a(n-18) -8236*a(n-19)
EXAMPLE
Some solutions for n=4
..0..2..1....0..0..0....0..2..1....0..0..0....1..1..2....0..2..1....0..2..1
..0..2..1....2..1..0....2..1..0....0..0..0....2..1..0....0..0..0....1..1..2
..0..0..0....1..1..2....0..0..0....2..1..0....0..0..0....0..0..0....0..0..0
..0..2..1....0..2..1....0..2..1....1..1..2....1..1..2....0..2..1....0..2..1
..0..2..1....0..0..0....2..1..0....0..2..1....2..1..0....0..0..0....1..1..2
CROSSREFS
Cf. A263373.
Sequence in context: A199581 A289609 A278815 * A120757 A134169 A052961
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 16 2015
STATUS
approved