a(n+1) = a(n) + p, where p is the largest prime less than a(n); a(1) = 3.

Terms

a(0) =3a(1) =5a(2) =8a(3) =15a(4) =28a(5) =51a(6) =98a(7) =195a(8) =388a(9) =771a(10) =1540a(11) =3071a(12) =6138a(13) =12271a(14) =24540a(15) =49073a(16) =98142a(17) =196271a(18) =392518a(19) =785021a(20) =1570038a(21) =3140045a(22) =6280086a(23) =12560153a(24) =25120300a(25) =50240589a(26) =100481176a(27) =200962343a(28) =401924670a(29) =803849309