%I #7 Feb 11 2022 19:17:58

%S 1,5,41,42,43,44,45,46,47,48,49,50,401,412,423,434,445,456,467,478,

%T 489,500,4001,4011,4021,4031,4041,4051,4061,4071,4081,4091,4102,4112,

%U 4122,4132,4142,4152,4162,4172,4182,4192,4203,4213

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

%t (#+6)/10&/@Select[Range[50000],PalindromeQ[#]&&IntegerDigits[#][[1]]==4&] (* _Harvey P. Dale_, Feb 11 2022 *)

%K nonn,base

%O 1,2

%A _Clark Kimberling_