A287877 Start with n and repeatedly apply the powertrain map x -> A133500(x); a(n) is the fixed point that is eventually reached, or -1 if the trajectory never reaches a fixed point.

1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 4, 8, 1, 9, 0, 8, 2, 1, 1, 3, 9, 8, 8, 0, 2, 0, 0, 0, 1, 4, 1, 0, 2, 1, 0, 0, 0, 0, 1, 5, 9, 5, 0, 0, 0, 0, 0, 0, 1, 6, 2, 1, 0, 0, 0, 0, 0, 0, 1, 7, 0, 0, 0, 7, 0, 0, 0, 0, 1, 8, 0, 1, 0, 0, 0, 0, 0, 0, 1, 9, 8, 2, 0, 0, 0, 0, 0, 0, 0, 1

Offset

1,2

Comments

It is conjectured that a fixed point is always reached.

It is also conjectured that the only fixed points are the numbers 0 through 9, 2592, and 24547284284866560000000000 (see A135385).

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A133500, A135385.

Sequence in context: A222210 A346511 A177894 * A175398 A175401 A175400

Adjacent sequences: A287874 A287875 A287876 * A287878 A287879 A287880

Keyword

nonn

Author

N. J. A. Sloane, Jun 16 2017

Status

approved