222051domain: NAppears in sequencesa(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=2, a(2)=1, and a(3)=3.at n=14A024961Base 4 digits are, in order, the first n terms of the periodic sequence with initial period 3,1,2,0.at n=8A037779a(n) = Sum_{k=0..4} 2^k * binomial(n,k).at n=25A389545