A372707 Smallest natural number requiring n applications of the map x -> 2^x mod x = A015910(x) to reach 0.

0, 1, 3, 18, 35, 207, 774, 1513, 2051, 8900, 13459, 25907, 34305, 88036, 153839, 382283, 397590, 636459, 844177, 1456073, 2426735, 7312307, 11716125, 14657311, 43165242, 52706549, 84955821, 188736643, 416569989, 953350161, 1617152961, 2541237149, 4847485412

Offset

0,3

Comments

A015910 is conjectured to contain every natural number except for 1, which would imply that this sequence has infinitely many terms.

Links

Kevin Ryde, Table of n, a(n) for n = 0..45

Kevin Ryde, C Code

Prog

(Python)
i = 0
c = [0]
for j in range(10**9):
    if c[-1] == i:
        print(f"a({i}) = {j}")
        i += 1
    c.append(1+c[pow(2, len(c), len(c))])
(C) /* See links. */

Crossrefs

Cf. A015910.

Sequence in context: A108169 A063116 A125284 * A097989 A039700 A069147

Adjacent sequences: A372704 A372705 A372706 * A372708 A372709 A372710

Keyword

nonn

Author

Bryle Morga, May 11 2024

Extensions

a(30)-a(32) from Michael S. Branicky, May 12 2024

Status

approved