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 A045177 #14 Feb 25 2023 20:37:50 %S A045177 10,27,35,51,53,54,55,65,70,77,85,102,110,132,136,138,139,142,147,152, %T A045177 160,176,178,179,180,190,195,202,210,227,235,256,258,259,266,268,269, %U A045177 271,273,274,276,278,279,280,290,295,326,328,329,330,340,345,351,353 %N A045177 Numbers whose base-5 representation contains exactly one 0 and one 2. %o A045177 (Python) %o A045177 from sympy.ntheory import count_digits %o A045177 def ok(n): c = count_digits(n, b=5); return c[0] == c[2] == 1 %o A045177 print([k for k in range(354) if ok(k)]) # _Michael S. Branicky_, Oct 27 2021 %Y A045177 Cf. A007091. %Y A045177 Subsequence of A039284. %K A045177 nonn,base %O A045177 1,1 %A A045177 _Clark Kimberling_