107775domain: NAppears in sequencesNumber of positive integers <= 2^n of form 5 x^2 + 10 y^2.at n=21A054180a(n) = 10^n + 6^n - 1.at n=5A155648Numbers n such that n and n+1 both have 18 divisors.at n=13A274360Haiku numbers.at n=22A321235