Question 24
A sequence of natural numbers is constructed by listing the first $4,$ then skipping one, listing the next $5,$ skipping $2,$ listing $6,$ skipping $3,$ and on the $n$th iteration, listing $n+3$ and skipping $n.$ The sequence begins $$
1,2,3,4,6,7,8,9,10,13.
$$ What is the $500{,}000$th number in the sequence?
1,2,3,4,6,7,8,9,10,13.
$$ What is the $500{,}000$th number in the sequence?