### Apocalyptic Numbers

logic

A number **n** is "apocalyptic" if the result of **2^n** contains a string of 3 consecutive 6s

(666 being the presumptive "number of the beast").

Create a function that takes a number **n** as input.

If the number is apocalyptic, find the start index of the **first/leftmost** 666 sequence in **2^n**...