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

Author

Franklin T. Adams-Watters, Jul 10 2009

Keywords

• nonn

Comments

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

Examples

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

Links

• Index entries for sequences that are fixed points of mappings

Crossrefs

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

Programs

PARI

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

Formula

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