From an old post, fits nice here too

Look at this image :

[link to upload.wikimedia.org]

This is the 24 repeated numbers of the digital root of Fibonacci sequence

In this image the two 369 equilateral triangles are figured but one could also draw :
two 147 equilateral triangles
two 258 equilateral triangles
one 111 equilateral triangle
one 888 equilateral triangle

So,
from 147 -> 2*147 + 1*111
from 258 -> 2*258 + 1*888
from 369 -> 2*369

It seems there's a triangle missing which is obviously 333 or 666 or 999

in 147, 1 in the smallest
in 258, 8 in the biggest
so in 369 it seems natural to choose the middle one

->

666 is The equilateral triangle who's shining by being not there in the digital root of Fibonacci sequence.