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Integers which have in Roman numerals more distinct symbols than any smaller number.
0

%I #26 Sep 11 2022 00:51:50

%S 1,4,14,44,144,444,1444

%N Integers which have in Roman numerals more distinct symbols than any smaller number.

%C Indices of record highs in A057226.

%C Smallest number whose Roman notation has exactly n distinct symbols.

%C The sequence is finite because 1444 is the smallest number using the symbols I,V,X,L,C,D,M.

%e For n = 3, a(3) = 14 because 14 = XIV which is the smallest number with 3 symbols in Roman notation.

%t kmax=1500; a={}; n=1; For[k=1, k<=kmax, k++, If[Length[DeleteDuplicates[Characters[RomanNumeral[k]]]] == n, AppendTo[a, k]; n++; k=1]]; a (* _Stefano Spezia_, Aug 26 2022 *)

%Y Cf. A057226, A038378.

%K nonn,fini,full,easy

%O 1,2

%A _Alain Cousquer_, Aug 24 2022