564950498domain: NAppears in sequencesNumerator of n^(n-2)/n!.at n=13A036502a(n) = 2*7^(n-1).at n=10A109808a(n) = 7*a(n-2), a(0) = 1, a(1) = 2.at n=21A123752a(n) = 2*49^n.at n=5A324266Numbers with 11 odd divisors.at n=21A368950