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 A228096 #10 Sep 09 2019 10:26:43
%S A228096 1,9,15,33,39,51,55,57,75,77,93,99,111,117,135,153,155,159,171,177,
%T A228096 195,315,333,339,351,355,357,375,393,399,513,515,519,531,535,537,551,
%U A228096 553,555,559,573,579,591,595,597,711,717,735,753,759,771,777,795
%N A228096 Numbers consisting of only odd digits such that no permutation of its digits yields a prime.
%C A228096 Apart from the first term, A061810 is a subsequence. Conjecture: a(n) ~ A061810(n). - _Charles R Greathouse IV_, Feb 15 2017
%H A228096 Jayanta Basu, <a href="/A228096/b228096.txt">Table of n, a(n) for n = 1..1000</a>
%e A228096 51 is a member since it consists of only odd digits and both 15 and 51 are composites.
%t A228096 Select[Range[800], And @@ OddQ[x = IntegerDigits[#]] && Count[FromDigits /@ Permutations[x], _?PrimeQ] == 0 &]
%t A228096 Table[FromDigits/@Select[Tuples[Range[1,9,2],n],NoneTrue[FromDigits/@ Permutations[#],PrimeQ]&],{n,3}]//Flatten (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 09 2019 *)
%Y A228096 Subsequence of A067013.
%Y A228096 Cf. A067013, A061810.
%K A228096 nonn,base
%O A228096 1,2
%A A228096 _Jayanta Basu_, Aug 10 2013