A291787 Trajectory of 45 under repeated application of the map k -> A291784(k).

45, 48, 56, 60, 80, 88, 92, 94, 95, 96, 112, 120, 160, 176, 184, 188, 190, 216, 252, 324, 378, 486, 567, 594, 738, 876, 1032, 1224, 1488, 1776, 2112, 2624, 2656, 2672, 2680, 2976, 3552, 4224, 5248, 5312, 5344, 5360, 5952, 7104, 8448, 10496, 10624

Offset: 0

Author

N. J. A. Sloane, Sep 02 2017

Keywords

• nonn

Comments

It may be that every trajectory under iteration of the map k -> A291784(k) which increases indefinitely will eventually merge with this sequence. This is certainly true for the terms 45 through 152 of A291788. - N. J. A. Sloane, Sep 24 2017

References

• Richard K. Guy, Unsolved Problems in Number Theory, 3rd Edition, Springer, 2004. See Section B41, p. 147.

Links

• N. J. A. Sloane, Table of n, a(n) for n = 0..10000
• N. J. A. Sloane, Three (No, 8) Lovely Problems from the OEIS, Experimental Mathematics Seminar, Rutgers University, Oct 05 2017, Part I, Part 2, Slides. (Mentions this sequence)
• C. R. Wall, Unbounded sequences of Euler-Dedekind means, Amer. Math. Monthly, 92 (1985), 587.

Crossrefs

Cf. A000010, A001615, A291784, A291785, A291786, A291788.

Formula

a(n) = 2*a(n-7) for n >= 35, which proves this is unbounded. [Guy, Wall]

Extensions

More terms from Hugo Pfoertner, Sep 03 2017