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 A370917 #10 Mar 15 2024 21:30:45
%S A370917 11,20,34,35,38,47,61,62,65,74,101,103,104,106,107,115,116,119,128,
%T A370917 142,143,146,155,182,184,185,187,188,196,197,200,209,223,224,227,236,
%U A370917 304,305,308,310,311,313,314,317,319,320,322,323,344,346,347,349,350,358
%N A370917 Positive integers whose ternary representation includes at least one 0, and every 0 is followed by 2.
%e A370917 The ternary representations of 11, 20, and 34 are 102, 202, and 1021.
%t A370917 Map[#[[1]] &, Select[Map[{#, #[[1]] > 0 && #[[1]] == #[[2]] &[{Length[
%t A370917 StringCases[#, "0"]], Length[StringCases[#, "02"]]}] &[
%t A370917 IntegerString[#, 3]]} &, Range[500]], #[[2]] &]]
%t A370917 (* _Peter J. C. Moses_, Mar 05 2024 *)
%Y A370917 Cf. A007089, A081605.
%Y A370917 Cf. A370916, A370918, A370919, A370920, A370921, A370922, A370923.
%K A370917 nonn,base
%O A370917 1,1
%A A370917 _Clark Kimberling_, Mar 15 2024