274878431233domain: NAppears in sequencesa(n) = 1^n + 2^n + 4^n.at n=19A001576a(n) = sigma_19(n), the sum of the 19th powers of the divisors of n.at n=3A013967Numerator of sum of -19th powers of divisors of n.at n=3A017701Numbers whose binary expansion has only the digit "1" as first, central and final digit.at n=19A135576