cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A267639 Number of nX3 0..1 arrays with every repeated value in every row and column unequal to the previous repeated value, and new values introduced in row-major sequential order.

Original entry on oeis.org

3, 18, 51, 189, 429, 1353, 2829, 8427, 16899, 49443, 96657, 282717, 542913, 1601355, 3032535, 9058395, 16953333, 51380925, 95168013, 292791555, 537249507, 1677388467, 3051796161, 9662000493, 17443801617, 55944191787, 100303228599
Offset: 1

Views

Author

R. H. Hardin, Jan 18 2016

Keywords

Comments

Column 3 of A267644.

Examples

			Some solutions for n=6
..0..0..1....0..1..1....0..1..1....0..0..1....0..1..1....0..1..0....0..0..1
..0..0..1....1..0..0....0..1..1....0..1..1....1..0..1....0..0..1....0..1..1
..1..1..0....1..1..0....1..0..0....1..1..0....1..1..0....1..1..0....1..1..0
..1..0..1....0..1..1....0..0..1....1..0..1....0..0..1....0..1..1....1..0..0
..0..1..0....1..0..0....1..1..0....0..1..0....0..1..0....1..0..0....0..0..1
..1..0..0....0..1..1....1..0..1....1..0..0....1..0..1....0..1..1....1..1..0
		

Crossrefs

Cf. A267644.

Formula

Empirical: a(n) = 2*a(n-1) +16*a(n-2) -33*a(n-3) -91*a(n-4) +198*a(n-5) +216*a(n-6) -523*a(n-7) -180*a(n-8) +576*a(n-9) -180*a(n-11)