Erdős problem 358

When $A_n = n$ , the function $f$ defined above counts the number of odd divisors of $n$ .

Sources

The source's own material, retained exactly.

6 retained statements36c6d0fef71a

FormalConjectures/ErdosProblems/

358.lean

Retained formal statement6 of 6

When $A_n = n$ , the function $f$ defined above counts the number of odd divisors of $n$ .

FormalConjectures/ErdosProblems/358.leanErdos358.f_id1 lineExact file

1Erdos358.f id = fun n => {d ∈ n.divisors | Odd d}.card

TextbookStatement only, no proof