A161780 Square array read by antidiagonals up. Redheffer type matrix. A007427 interleaved with k-1 zeros in the columns.

1, -2, 1, -2, 1, 1, 1, 0, 0, 1, -2, -2, 1, 0, 1, 4, 0, 0, 0, 0, 1, -2, -2, 0, 1, 0, 0, 1, 0, 0, -2, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 1, 4, 0, 0, 0, 0, 0, 0, 0, 0, 1, -2, -2, -2, -2, 0, 1, 0, 0, 0, 0, 1, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -2, 4, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 4, 0, 1

Offset: 1

Author

Mats Granvik, Jun 19 2009

Keywords

• sign
• tabl

Comments

The determinant of this matrix is A006218.

Examples

			Table begins:
..1..1..1..1..1..1..1..1
.-2..1..0..0..0..0..0..0
.-2..0..1..0..0..0..0..0
..1.-2..0..1..0..0..0..0
.-2..0..0..0..1..0..0..0
..4.-2.-2..0..0..1..0..0
.-2..0..0..0..0..0..1..0
..0..1..0.-2..0..0..0..1
		

Crossrefs

Cf. A007427, A006218, A002321.

Programs

Excel

=if(row()=1;1;if(mod(row();column())=0;1*lookup(row()/column();A000027;A007427);0))