659706976665domain: NAppears in sequencesBase 4 digits are, in order, the first n terms of the periodic sequence with initial period 2,1.at n=19A037489Evaluation of the polynomials given by the Riordan square of the Fibonacci sequence with a(0) = 1 (A193737) at 1/2 and normalized with 2^n.at n=20A330795