A074970 Number of steps to reach the first integer starting with sigma(n)/n and iterating the map x -> x*ceiling(x), or -1 if no integer is ever reached.

0, 1, 2, 2, 18, 0, 3, 2, 3, 3, 26, 1, 9, 3, 7, 3, 6, 3, 56, 10, 9, 15, 42, 2, 10, 3, 3, 0, 38, 17, 79, 3, 27, 16, 8, 8, 200, 76, 4, 3, 36, 2, 4, 15, 4, 51, 11, 2, 4, 6, 22, 42, 43, 5, 25, 2, 4, 103, 37, 17, 18, 20, 8, 3, 22, 25, 225, 59, 6, 13, 20, 4, 182, 13, 8

Offset: 1

Author

Reinhard Zumkeller, Oct 05 2002

Keywords

• nonn

Comments

a(p) = A073524(p) for primes p.

Examples

			a(26)=3 since (26+13+2+1)/26=21/13 -> 42/13 -> 168/13 -> 168.
		

Crossrefs

Cf. A000203, A009194, A073524.

Extensions

a(20) corrected by and more terms from Jinyuan Wang, Jan 15 2022