1952613domain: NAppears in sequencesa(n) = 5^n - 2^n.at n=9A005057Sum of numbers that can be written as t*n + u*(n+1) for nonnegative integers t,u in exactly four ways.at n=25A076457Difference of two positive 9th powers.at n=9A181128Monotonic ordering of nonnegative differences 5^i-8^j, for 40>= i>=0, j>=0.at n=36A192197