A381963 Irregular triangle read by rows, where row n lists the iterates of f(x), starting at x = n until f(x) < 10, where f(x) is the digital sum of x (A007953).
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 11, 2, 12, 3, 13, 4, 14, 5, 15, 6, 16, 7, 17, 8, 18, 9, 19, 10, 1, 20, 2, 21, 3, 22, 4, 23, 5, 24, 6, 25, 7, 26, 8, 27, 9, 28, 10, 1, 29, 11, 2, 30, 3, 31, 4, 32, 5, 33, 6, 34, 7, 35, 8, 36, 9, 37, 10, 1, 38, 11, 2, 39, 12, 3
Offset: 0
Examples
Triangle begins: n\k| 0 1 2 --------------- 0 | 0; 1 | 1; 2 | 2; 3 | 3; 4 | 4; 5 | 5; 6 | 6; 7 | 7; 8 | 8; 9 | 9; 10 | 10, 1; 11 | 11, 2; 12 | 12, 3; 13 | 13, 4; 14 | 14, 5; 15 | 15, 6; 16 | 16, 7; 17 | 17, 8; 18 | 18, 9; 19 | 19, 10, 1; 20 | 20, 2; ...
Links
- Paolo Xausa, Table of n, a(n) for n = 0..11648 (rows 0..4000 of triangle, flattened).