A228096 - OEIS

%I #10 Sep 09 2019 10:26:43

%S 1,9,15,33,39,51,55,57,75,77,93,99,111,117,135,153,155,159,171,177,

%T 195,315,333,339,351,355,357,375,393,399,513,515,519,531,535,537,551,

%U 553,555,559,573,579,591,595,597,711,717,735,753,759,771,777,795

%N Numbers consisting of only odd digits such that no permutation of its digits yields a prime.

%C Apart from the first term, A061810 is a subsequence. Conjecture: a(n) ~ A061810(n). - _Charles R Greathouse IV_, Feb 15 2017

%H Jayanta Basu, <a href="/A228096/b228096.txt">Table of n, a(n) for n = 1..1000</a>

%e 51 is a member since it consists of only odd digits and both 15 and 51 are composites.

%t Select[Range[800], And @@ OddQ[x = IntegerDigits[#]] && Count[FromDigits /@ Permutations[x], _?PrimeQ] == 0 &]

%t 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 Subsequence of A067013.

%Y Cf. A067013, A061810.

%K nonn,base

%O 1,2

%A _Jayanta Basu_, Aug 10 2013