A140705 A000012 * A051731^4.
1, 5, 1, 9, 1, 1, 19, 5, 1, 1, 23, 5, 1, 1, 1, 39, 9, 5, 1, 1, 1, 43, 9, 5, 1, 1, 1, 1, 63, 19, 5, 5, 1, 1, 1, 1, 73, 19, 9, 5, 1, 1, 1, 1, 1, 89, 23, 9, 5, 5, 1, 1, 1, 1, 1, 93, 23, 9, 5, 5, 1, 1, 1, 1, 1, 1
Offset: 1
Examples
First few rows of the triangle are: 1; 5, 1; 9, 1, 1; 19, 5, 1, 1; 23, 5, 1, 1, 1; 39, 9, 5, 1, 1, 1; 43, 9, 5, 1, 1, 1, 1; 63, 19, 5, 5, 1, 1, 1, 1; ...
Formula
Extensions
a(60) split into 5,1 by Georg Fischer, Aug 27 2023
Comments