Trajectory of 23 under map x->x + (x-with-digits-reversed).

Terms

a(0) =23a(1) =55a(2) =110a(3) =121a(4) =242a(5) =484a(6) =968a(7) =1837a(8) =9218a(9) =17347a(10) =91718a(11) =173437a(12) =907808a(13) =1716517a(14) =8872688a(15) =17735476a(16) =85189247a(17) =159487405a(18) =664272356a(19) =1317544822a(20) =3602001953a(21) =7193004016a(22) =13297007933a(23) =47267087164