Recamán sequence simple.

recamán.py

import sys
from collections import Counter


def main():
    next_location = 0
    history = Counter()
    for i in range(1, 100):
        print(next_location)
        next_location = racaman(next_location, i, history)
    return


def racaman(location: int, iteration: int, history: dict):
    history.update([location])
    if iteration >= location:
        return location + iteration
    if history[location - iteration] == 0:
        return location - iteration
    return location + iteration


if __name__ == '__main__':
    main()
    sys.exit(0)