The Devil's Calculator DLC Level Submission
An Independent Educational Math game where players try to interpolate functions and use them to calculate the same integer repeatedly. We wanted to give educators a forum to contribute levels (once the game is beaten, that individual then unlocks the ability to add levels themselves). Examples of programmed levels can be seen here: https://bit.ly/2N5GXAR

The interface of the game is reminiscent of a scientific calculator and the objective of each level is to calculate the number 666 using all of the up to 3 available symbols that each represents a mystery function. Graphing results and recognizing patterns within these functions allow players to strategize on how they will use these functions together to generate the integer 666, while avoiding buttons that are disallowed for that level. The M1, M2 and M3 keys allow players to save their computations in memory as they tackle the level. (screenshot below)

You are free to submit as many levels as you like.
For the credits, put "anonymous" if you do not wish to be credited
Bio
Δ Function (unary:a)
The first function introduced, a unary function that takes one variable: i.e. a! would be factorial (or simply write a description of the function and we will code it by hand). Leave blank if you do not wish for it to be involved in the level.
ψ Function (binary:a,b)
The second function introduced, a binary function that takes two variables: i.e. a*b would be multiplication (or simply write a description of the function and we will code it by hand). Leave blank if you do not wish for it to be involved in the level.
φ Function (unary:a)
The third function introduced, a unary function that takes one variable that represents the index of an integer sequence: i.e. prime numbers. Write a description (or put the url from OEIS) and we will code by hand. Must only accept and return integers. Leave blank if you do not wish for it to be involved in the level.