65457domain: NAppears in sequencesa(0)=1, a(1)=1, a(n) = 9*a(n/2) for even n >= 2, and a(n) = 8*a((n-1)/2) + a((n+1)/2) for odd n >= 3.at n=42A116526Smallest k such that the number k^n in its decimal representation has a prime number of copies of the digit d for each d from 0 through 9.at n=28A217051