878905domain: NAppears in sequencesa(1)=1, a(n) = a(n-1) + (p-1)*p^(n/2-1) if n is even, otherwise a(n) = a(n-1) + p^((n-1)/2), where p=5.at n=16A133629Number of circular arrangements of the first n positive integers such that adjacent terms have absolute difference 1 or 4.at n=48A336749