total segment toggles as a 7-segment display counts up from 1234 to 6789 - https://twitter.com/wacnt/status/566024138481881088

segments.py

"""
Layout:
 0 
1 2
 3
4 5
 6
"""

from itertools import product
segments = ['1110111','0010010','1011101','1011011','0111010','1101011','0101111','1010010','1111111','1111010']

toggles = {}
for a,b in product(range(10),repeat=2):
    t = 0
    for da,db in zip(segments[a],segments[b]):
        if da!=db:
            t += 1
    toggles[(str(a),str(b))] = t
    
total = 0
for old,new in zip(range(1234,6789),range(1235,6790)):
    for dold,dnew in zip(str(old),str(new)):
        total += toggles[(dold,dnew)]
print(total)

20976