999960domain: NAppears in sequencesa(n)^2 + 1 is largest prime of the form x^2 + 1 <= 10^n.at n=11A083845a(n) = 1600*n^2 - 40.at n=24A158773The largest n-digit number whose last k digits are divisible by k for k = 1..n.at n=5A220490Least positive integer whose square root starts with just n odd decimal digits.at n=18A334161