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Liam's house has a staircase with $12$ steps. He can go down the steps one at a time or two at a time.
For example, he could go down $1$ step, then $1$ step, then $2$ steps, then $2$, $2$, $1$, $1$, $1$, $1$.
In how many different ways can Liam go down the $12$ steps, taking one or two steps at a time?
The well known Fibonacci sequence is 1 ,1, 2, 3, 5, 8, 13, 21.... How many Fibonacci sequences can you find containing the number 196 as one of the terms?
How many different ways can I lay 10 paving slabs, each 2 foot by 1 foot, to make a path 2 foot wide and 10 foot long from my back door into my garden, without cutting any of the paving slabs?
Here are some circle bugs to try to replicate with some elegant programming, plus some sequences generated elegantly in LOGO.