Question 24
Prove that each number in the sequence $12,1122,111222,\ldots$ is a product of two consecutive whole numbers.
In the nth term there are n consecutive digits 1 followed by n consecutive digits 2, for every positive integer n. Submit a proof; this item is marked manually.
In the nth term there are n consecutive digits 1 followed by n consecutive digits 2, for every positive integer n. Submit a proof; this item is marked manually.