A243824 Two-column array A(n,s) of pairs (n,s) read by row where s is the smallest seed number such that the Reverse and Add! trajectory of s contains n (excluding cases where n=s).
2, 1, 4, 1, 6, 3, 8, 1, 10, 5, 11, 5, 12, 3, 14, 7, 16, 1, 18, 9, 22, 5
Offset: 2
Examples
A(10,1)=16 is in the array because 16 is the 9th number appearing in the Reverse and Add! trajectory of a smaller number. A(10,2)=1 is in the array because 1 + 1 = 2, 2 + 2 = 4, 4 + 4 = 8, 8 + 8 = 16, so 1 is the smallest seed number whose Reverse and Add! trajectory contains 16. Array begins: 2 1 4 1 6 3 8 1 10 5 11 5 12 3 14 7 16 1 18 9 22 5
Links
- Felix Fröhlich, C++ program for this sequence