a(1) = 5, a( n) = prime(a(n-1)) - a(n-1).

Terms

a(0) =5a(1) =6a(2) =7a(3) =10a(4) =19a(5) =48a(6) =175a(7) =864a(8) =5837a(9) =51800a(10) =584259a(11) =8124352a(12) =135854841a(13) =2676859186a(14) =61120545021