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

2,1

Links

Table of n, a(n) for n=2..23.

Felix Fröhlich, C++ program for this sequence

Example

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

Crossrefs

Cf. A006960, A023109, A033665, A063048, A070788, A077594.

Sequence in context: A332792 A118275 A328612 * A146938 A147418 A146386

Adjacent sequences: A243821 A243822 A243823 * A243825 A243826 A243827

Keyword

nonn,base,tabf,more

Author

Felix Fröhlich, Jun 11 2014

Status

approved