A173204 a(n) is the smallest number which has in its English name the letter "n" in the n-th position beginning the count from the end.
7, 1, 20, 9, 17, 19, 24, 19, 91, 94, 93, 101, 104, 103, 111, 115, 113, 117, 124, 123, 173, 923, 973, 1101, 1104, 1103, 1111, 1115, 1113, 1117, 1124, 1123, 1173, 1323, 1373, 9323, 9373, 17373, 19173, 19323, 19373, 91373, 93323
Offset: 1
Examples
a(1) = seveN, a(2) = oNe, a(3) = tweNty, a(4)= Nine, a(5) = seveNteen, etc.
Crossrefs
Programs
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Mathematica
ePos[n_] := Flatten@Position[DeleteCases[Reverse@Characters@IntegerName[n, "Words"], a_ /; MemberQ[{" ", "\[Hyphen]"}, a]], "n"]; t = {}; i = 1; Monitor[Table[Do[If[MemberQ[ePos[i], n], Return[lst = AppendTo[t, i]; i = 1; lst], i++], \[Infinity]], {n, 1, 43, 1}] // Last, {ProgressIndicator[n, {1, 43}], n, i}] (* Robert P. P. McKone, Feb 07 2022 *)
Extensions
More terms from Robert P. P. McKone, Feb 08 2022