A162696 Trajectory of 1 under morphism taking n to sorted divisors of n+1.

1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 3, 1, 5, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 2, 3, 6, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 3, 1, 5, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 3, 1, 5, 1, 2, 1, 3, 1, 2, 1, 3, 1, 2, 4, 1, 7, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2

Offset

1,2

Comments

1 -> 1,2; 2->1,3; 3->1,2,4; ...

Links

Table of n, a(n) for n=1..105.

Index entries for sequences that are fixed points of mappings

Formula

a(A117160(k+1)) = k (this is the first occurrence of k in the sequence). - Rémy Sigrist, Jan 14 2023

Example

1 -> 1,2 -> 1,2,1,3 -> 1,2,1,3,1,2,1,2,4 -> ...

Prog

(PARI) v=[1, 2]; for(i=2, 60, v=concat(v, divisors(v[i]+1))); v

Crossrefs

Cf. A007001, A001511, A027750, A112682, A117160.

Sequence in context: A176207 A059130 A094959 * A370265 A364447 A309978

Adjacent sequences: A162693 A162694 A162695 * A162697 A162698 A162699

Keyword

nonn

Author

Franklin T. Adams-Watters, Jul 10 2009

Status

approved