a(0) = 1; thereafter a(n) = 2*a(n-1) + 1, with digits rearranged into nondecreasing order.

Terms

a(0) =1a(1) =3a(2) =7a(3) =15a(4) =13a(5) =27a(6) =55a(7) =111a(8) =223a(9) =447a(10) =589a(11) =1179a(12) =2359a(13) =1479a(14) =2599a(15) =1599a(16) =1399a(17) =2799a(18) =5599a(19) =11199a(20) =22399a(21) =44799a(22) =58999a(23) =117999a(24) =235999a(25) =147999a(26) =259999a(27) =159999a(28) =139999a(29) =279999