Function growth_end 

fn growth_end(
    j1: i32,
    j2: i32,
    m1: i32,
    m2: i32,
    minimum: i32,
    stop: i32,
) -> i32

The first j in minimum + 1..=stop at which the upward recurrence of the row (j1 j2 j; m1 m2 -m1-m2) stops growing in magnitude, or stop + 1. Iterates the ratio of consecutive symbols, which needs no closed-form start value.