A228096 Numbers consisting of only odd digits such that no permutation of its digits yields a prime.

1, 9, 15, 33, 39, 51, 55, 57, 75, 77, 93, 99, 111, 117, 135, 153, 155, 159, 171, 177, 195, 315, 333, 339, 351, 355, 357, 375, 393, 399, 513, 515, 519, 531, 535, 537, 551, 553, 555, 559, 573, 579, 591, 595, 597, 711, 717, 735, 753, 759, 771, 777, 795

Offset

1,2

Comments

Apart from the first term, A061810 is a subsequence. Conjecture: a(n) ~ A061810(n). - Charles R Greathouse IV, Feb 15 2017

Links

Jayanta Basu, Table of n, a(n) for n = 1..1000

Example

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

Mathematica

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

Crossrefs

Subsequence of A067013.

Cf. A067013, A061810.

Sequence in context: A091296 A107076 A155775 * A111148 A125216 A058505

Adjacent sequences: A228093 A228094 A228095 * A228097 A228098 A228099

Keyword

nonn,base

Author

Jayanta Basu, Aug 10 2013

Status

approved