This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A349887 #11 Dec 04 2021 12:12:20
%S A349887 0,1,5,8,9,10,20,22,24,26,31,35,38,39,41,45,48,49,51,55,58,59,61,65,
%T A349887 68,69,80,82,84,86,90,92,94,96,200,202,204,206,230,232,234,236,240,
%U A349887 242,244,246,250,252,254,256,260,262,264,266,400,402,404,406,430,432,434,436
%N A349887 Numbers which, when written in English, contain exactly one instance of the letter E.
%e A349887 ZERO has one E, ONE also, but not TWO (no E) nor THREE (2 Es).
%o A349887 (Python)
%o A349887 from num2words import num2words
%o A349887 def ok(n): return num2words(n).count("e") == 1
%o A349887 print([k for k in range(667) if ok(k)]) # _Michael S. Branicky_, Dec 04 2021
%Y A349887 Cf. A006933 ('Eban' numbers).
%K A349887 word,nonn
%O A349887 1,3
%A A349887 _Eric Angelini_, Dec 04 2021