99980001

Appears in sequences

• a(n) = (10^n - 1)^2.at n=4A059988
• Largest n-digit square.at n=7A061433
• Largest n-digit perfect power.at n=7A069659
• Squares arising as a concatenation of k and 9's complement of k.at n=10A084006
• Numbers n that can be chopped into two parts, which when added and squared result in n.at n=19A102766
• Numbers whose square is the concatenation of two numbers k and k-4.at n=7A115443
• a(n) is the largest n-digit square whose sum of digits is also a square.at n=7A180737
• Numbers which when chopped into two parts with equal length, added and squared result in the same number.at n=10A238237
• Numbers k such that k+1 concatenated with k is a square.at n=6A328089
• Numbers k = x.y which when split into two parts x and y of equal length, added and squared result in the same number k, '.' means concatenation, and the second part y starts with 0.at n=2A350918