966441domain: NAppears in sequencesTetranacci numbers A073817 without the leading term 4.at n=20A001648Tetranacci numbers with different initial conditions: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) starting with a(0)=4, a(1)=1, a(2)=3, a(3)=7.at n=21A073817Floor((quadronacci ratio)^n).at n=20A125898