Question 25
A number is formed using only the digits 1, 2, 3, 4 and 5. Digits may repeat, but adjacent digits cannot be equal. Once an ordered pair of adjacent digits occurs, that same pair in the same order cannot occur again. How many digits are in the largest such number?
Answer entry: enter the whole number only, without units. The paper uses four shaded digits with leading zeros; ordinary integer entry is accepted here.
Answer entry: enter the whole number only, without units. The paper uses four shaded digits with leading zeros; ordinary integer entry is accepted here.