The missing term in the series 1, 4, 27, 16, ?, 36, 343, … is

Concept

An interleaved series combines two independent sequences by alternating their terms.

To solve it, separate the terms at odd positions from those at even positions and identify the rule in each subsequence.

Application

1. At odd positions: 1 = 13, 27 = 33, ? = 53, and 343 = 73.

2. At even positions: 4 = 22, 16 = 42, and 36 = 62.

3. The fifth term belongs to the odd-position subsequence, so its value is 53 = 125.

Cross-check

Placing 125 back gives odd-position cubes 13, 33, 53, 73 and even-position squares 22, 42, 62; both subsequences progress consistently.

Result

Therefore, the missing term is 125.