43685domain: NAppears in sequencesa(n) = Sum_{k=1..n} ceiling(k^4/n).at n=20A014816Number of primes less than 10^n having at least one digit 3.at n=5A091647a(n) = (A006935(n) - 1) / ord(2,A006935(n)/2), where ord(k,m) is the multiplicative order of k modulo m.at n=16A350083