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, 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

Author

R. H. Hardin, Oct 16 2015

Keywords

• nonn

Comments

Column 2 of A263373.

Examples

			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
		

Links

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

Crossrefs

Cf. A263373.

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)