@registry.register('A000073')
def tribonacci() -> Iterable[int]:
    'Tribonacci numbers.'
    (yield 0)
    (yield 0)
    (yield 1)
    p3: int = 0
    p2: int = 0
    p1: int = 1
    while True:
        curr: int = ((p1 + p2) + p3)
        (yield curr)
        (p1, p2, p3) = (curr, p1, p2)
Tribonacci numbers.
@registry.register('A000073')
def tribonacci() -> Iterable[int]:
    
    (yield 0)
    (yield 0)
    (yield 1)
    p3: int = 0
    p2: int = 0
    p1: int = 1
    while True:
        curr: int = ((p1 + p2) + p3)
        (yield curr)
        (p1, p2, p3) = (curr, p1, p2)