1162268326domain: NAppears in sequencesa(n) = 3^n + n^3.at n=19A001585Numbers of the form p^3 + 3^p for p prime.at n=7A097059Numbers of the form a^b+b^a, a and b are odd primes, b > a.at n=7A173055Numbers of the form a^b+b^a, a and b are primes.at n=20A173056