A141157 Triangle read by rows, A000012 * A140207.
1, 2, 1, 3, 2, 2, 4, 3, 4, 3, 5, 4, 6, 6, 5, 6, 5, 8, 9, 10, 7, 7, 6, 10, 12, 15, 14, 11, 8, 7, 12, 15, 20, 21, 22, 15, 9, 8, 14, 18, 25, 28, 33, 30, 22, 10, 9, 16, 21, 30, 35, 44, 45, 44, 30, 11, 10, 18, 24, 35, 42, 55, 60, 66, 60, 42, 12, 11, 20, 27, 40, 49, 66, 75, 88, 90, 84, 56
Offset: 0
Examples
First few rows of the triangle are: 1; 2, 1; 3, 2, 2; 4, 3, 4, 3; 5, 4, 6, 6, 5; 6, 5, 8, 9, 10, 7; 7, 6, 10, 12, 15, 14, 11; 8, 7, 12, 15, 20, 21, 22, 15; 9, 8, 14, 18, 25, 28, 33, 30, 22; 10, 9, 16, 21, 30, 35, 44, 45, 44, 30; ...
Formula
Extensions
a(60) split and more terms from Georg Fischer, May 29 2023
Comments