a(1)=1, then a(n)=2*a(n-1) if a(n-1) is prime, a(n)=a(n-1)+1 otherwise.

Terms

a(0) =1a(1) =2a(2) =4a(3) =5a(4) =10a(5) =11a(6) =22a(7) =23a(8) =46a(9) =47a(10) =94a(11) =95a(12) =96a(13) =97a(14) =194a(15) =195a(16) =196a(17) =197a(18) =394a(19) =395a(20) =396a(21) =397a(22) =794a(23) =795a(24) =796a(25) =797a(26) =1594a(27) =1595a(28) =1596a(29) =1597