A131398 3*A007318 - A097806 - A000012.
1, 1, 1, 2, 4, 1, 2, 8, 7, 1, 2, 11, 17, 10, 1, 2, 14, 29, 29, 13, 1, 2, 17, 44, 59, 44, 16, 1, 2, 20, 62, 104, 104, 62, 19, 1, 2, 23, 83, 167, 209, 167, 83, 22, 1, 2, 26, 107, 251, 377, 377, 251, 107, 25, 1
Offset: 0
Examples
First few rows of the triangle are: 1; 1, 1; 2, 4, 1; 2, 8, 7, 1; 2, 11, 17, 10, 1; 2, 14, 29, 29, 13, 1; ...
Comments