A168261 Triangle read by rows, A115361 * the diagonalized variant of A018819.

1, 1, 1, 0, 0, 2, 1, 1, 0, 2, 0, 0, 0, 0, 4, 0, 0, 2, 0, 0, 4, 0, 0, 0, 0, 0, 0, 6, 1, 1, 0, 2, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 4, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14, 0, 0, 2, 0, 0, 4, 0, 0, 0, 0, 0, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 20

Offset: 1

Author

Gary W. Adamson, Nov 21 2009

Keywords

• nonn
• tabl

Comments

Row sums = A018819 starting with offset 1; (1, 2, 2, 4, 4, 6, 6, 10, 10,...).

Equals the eigensequence of triangle A115361.

Rightmost diagonal = A018819.

Sum of n-th row terms = rightmost term of next row.

Examples

			First few rows of the triangle =
1;
1, 1;
0, 0, 2;
1, 1, 0, 2;
0, 0, 0, 0, 4;
0, 0, 2, 0, 0, 4;
0, 0, 0, 0, 0 0, 6;
1, 1, 0, 2, 0, 0, 0, 6;
0, 0, 0, 0, 0, 0, 0, 0, 10;
0, 0, 0, 0, 4, 0, 0, 0, 0, 10;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14;
0, 0, 2, 0, 0, 4, 0, 0, 0, 0, 0, 14;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 20;
0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 20;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 26;
1, 1, 0, 2, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 26;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 36;
...
		

Crossrefs

Cf. A115361, A018819.

Formula

Equals M*Q as infinite lower triangular matrices, where M = triangle A115361, and Q = the diagonalized variant of A018819 such that (1, 1, 2, 2, 4, 4, 6, 6,...) = rightmost diagonal with the rest zeros.