Built with from Grav and Hugo
$1,11,21,1211,111221,\cdots$
Don’t think too much. Just read and count it in English.
The Fibonacci sequence is given by
$$F_0=0$$ $$F_1=1$$ $$F_{n+2}=F_{n+1}+F_n$$
File: Material/fibonacci.sagews
Material/fibonacci.sagews