a(n)=(s(n)+4)/10, where s(n)=n-th base 10 palindrome that starts with 6.

Terms

a(0) =1a(1) =7a(2) =61a(3) =62a(4) =63a(5) =64a(6) =65a(7) =66a(8) =67a(9) =68a(10) =69a(11) =70a(12) =601a(13) =612a(14) =623a(15) =634a(16) =645a(17) =656a(18) =667a(19) =678a(20) =689a(21) =700a(22) =6001a(23) =6011a(24) =6021a(25) =6031a(26) =6041a(27) =6051a(28) =6061a(29) =6071