5226496domain: NAppears in sequencesa(n) = 4^(floor(n/2))+4^(floor(n/2)-1)-4^(floor((n-1)/3)).at n=20A170833a(n) = 4^(floor(n/2))+4^(floor(n/2)-1)-4^(floor((n-1)/3)).at n=21A170833