Respuesta :
Answer: C.They are consecutive terms in the Fibonacci sequence.
Step-by-step explanation:
The Fibonacci Sequence is the series of numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...
Each number is the sum of the two numbers that come before it.
The square pyramidal numbers are: 1, 5, 14, 30, 55, 91, 140, 204, 285, 385, 506, 650, 819, ...
Therefore, we can see given numbers of cactus , 13 and 21 respectively are the consecutive terms of Fibonacci sequence.
Thus, Option C is the right answer.