Posted by **Arnau** on Thursday, May 2, 2013 at 5:48am.

Given a positive integer n, let S(n) denote the digit sum of n. Consider the sequence of numbers given by

n₁ = S(n)

nk = S(nk−1)k≥2

For how many positive integers n ≤ 2013 does the sequence {nk} contain the number 9?

## Answer This Question

## Related Questions

- maths - Given a positive integer n, let S(n) denote the digit sum of n. Consider...
- Math - A smooth partition of the integer n is a set of positive integers a 1 ,a ...
- Math (algebra) - Suppose a and b are positive integers satisfying 1≤a&#...
- Maths - Suppose a and b are positive integers satisfying 1≤a≤31, 1&#...
- algebra - Call a positive integer N ≥ 2 “special” if for every k such that...
- geometry - A smooth partition of the integer n is a set of positive integers a1,...
- Algebra - Let S(N) denote the digit sum of the integer N. Let M denote the ...
- math - Let S(N) denote the digit sum of the integer N. As N ranges over all 3-...
- math - Let S(N) denote the digit sum of the integer N. As N ranges over all 3-...
- Algebra - How many positive integers n≤1000 cannot be written in the form ...

More Related Questions