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%I #7 Nov 29 2014 13:06:41
%S 1,4,31,32,33,34,35,36,37,38,39,40,301,312,323,334,345,356,367,378,
%T 389,400,3001,3011,3021,3031,3041,3051,3061,3071,3081,3091,3102,3112,
%U 3122,3132,3142,3152,3162,3172,3182,3192,3203,3213
%N (s(n)+7)/10, where s(n)=n-th base 10 palindrome that starts with 3.
%t palQ[n_]:=Module[{idn=IntegerDigits[n]},idn==Reverse[idn]]; (#+7)/10&/@ Select[Range[40000],palQ[#]&&First[IntegerDigits[#]]==3&] (* _Harvey P. Dale_, Nov 29 2014 *)
%K nonn,base
%O 1,2
%A _Clark Kimberling_