This seems intuitively obvious, not a miracle.
Take every other element in a series that has any regularish omnidirectional trend, alternate addition and subtraction, and you are quite likely to end up with a zero convergence.
Take every other element in a series that has any regularish omnidirectional trend, alternate addition and subtraction, and you are quite likely to end up with a zero convergence.
e.g. 1+4-9+16-25+36-49=-26
just get used to it.