Numbers n of the form k + reverse(k) for exactly three k.

Terms

a(0) =33a(1) =176a(2) =303a(3) =323a(4) =343a(5) =363a(6) =383a(7) =403a(8) =423a(9) =443a(10) =463a(11) =483a(12) =1221a(13) =1616a(14) =1636a(15) =1656a(16) =1676a(17) =1696a(18) =1716a(19) =1736a(20) =1756a(21) =1776a(22) =1796a(23) =2761a(24) =3003a(25) =4983a(26) =12021a(27) =12421a(28) =12621a(29) =12821