47301104551domain: NAppears in sequencesSomos-4 sequence: a(0)=a(1)=a(2)=a(3)=1; for n >= 4, a(n) = (a(n-1) * a(n-3) + a(n-2)^2) / a(n-4).at n=17A006720A (25,-29) Somos-4 sequence.at n=7A188313