Somos-4 recurrence with a(i)=2^i for 0<=i<=3.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =32a(5) =96a(6) =448a(7) =2944a(8) =15104a(9) =160768a(10) =1565696a(11) =16812032a(12) =341250048a(13) =5081473024a(14) =128940408832