29451204315domain: NAppears in sequencesBase-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,2,3.at n=17A037604a(n) = (8^n - 1)*3/7.at n=12A083713a(n) = Sum[2^(A001651(i-1)-1), {i,1,n}].at n=23A113836Expansion of x*(1 + x)/((1-2*x)*(1+x+x^2)).at n=36A294627