A113126 A simple 4-diagonal matrix.

1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 0, 2, 3, 4, 5, 0, 0, 3, 4, 5, 6, 0, 0, 0, 4, 5, 6, 7, 0, 0, 0, 0, 5, 6, 7, 8, 0, 0, 0, 0, 0, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 7, 8, 9, 10, 0, 0, 0, 0, 0, 0, 0, 8, 9, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 9, 10, 11, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 11, 12, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 0

Author

Paul Barry, Oct 14 2005

Keywords

• easy
• nonn
• tabl

Comments

Row sums are A113127. Diagonal sums are A109613. Diagonals are A000027.

Examples

			Triangle begins
1;
1,2;
1,2,3;
1,2,3,4;
0,2,3,4,5;
0,0,3,4,5,6;
0,0,0,4,5,6,7;
0,0,0,0,5,6,7,8;
0,0,0,0,0,6,7,8,9;
		

Crossrefs

Cf. A113125.

Formula

Number triangle where column k has g.f. (1+x+x^2+x^3)(k+1)x^k.