A158950 Triangle read by rows, A158948 * (an infinite lower triangular matrix with A000071 prefaced with a 1 as the right border; and the rest zeros).

1, 1, 1, 2, 0, 2, 2, 1, 0, 4, 3, 0, 2, 0, 7, 3, 1, 0, 4, 0, 12, 4, 0, 2, 0, 7, 0, 20, 4, 1, 0, 4, 0, 12, 0, 33, 5, 0, 2, 0, 7, 0, 20, 0, 54, 5, 1, 0, 4, 0, 12, 0, 33, 0, 88, 6, 0, 2, 0, 7, 0, 20, 0, 54, 0, 143

Offset: 1

Author

Gary W. Adamson, Mar 31 2009

Keywords

• eigen
• nonn
• tabl

Comments

Row sums = A000071 starting with nonzero terms: (1, 2, 4, 7, 12,...) As a property of eigentriangles, sum of n-th row terms = rightmost term of next row.

Examples

			First few rows of the triangle =
1;
1, 1;
2, 0, 2;
2, 1, 0, 4;
3, 0, 2, 0, 7;
3, 1, 0, 4, 0, 12;
4, 0, 2, 0, 7, 0, 20;
4, 1, 0, 4, 0, 12, 0, 33;
5, 0, 2, 0, 7, 0, 20, 0, 54;
5, 1, 0, 4, 0, 12, 0, 33, 0, 88;
6, 0, 2, 0, 7, 0, 20, 0, 54, 0, 143;
6, 1, 0, 4, 0, 12, 0, 33, 0, 88, 0, 232;
7, 0, 2, 0, 7, 0, 20, 0, 54, 0, 143, 0, 376;
7, 1, 0, 4, 0, 12, 0, 33, 0, 88, 0, 232, 0, 609;
...
Row 4 = (2, 1, 0, 4) = termwise products of (2, 1, 0, 1) and (1, 1, 2, 4);
where (2, 1, 0, 1) = row 4 of triangle A158948, and (1, 1, 2, 4) = the 3 nonzero terms of A000071 prefaced with a 1.
		

Crossrefs

A158948, A000071

Formula

Triangle read by rows, A158948 * M; where M = (an infinite lower triangular matrix with A000071 prefaced with a 1 as the right border, and the rest zeros). M = (1; 0,1; 0,0,2; 0,0,0,4; 0,0,0,7;...).