login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A225421 Prime numbers consisting of only odd digits such that there is only one permutation of its digits that produces a prime number. 1

%I

%S 3,5,7,11,19,53,59,151,353,557,599,773,997,5557,7559,11119,15559,

%T 59999,71777,75553,79999,99991,191999,511111,555557,575557,775777,

%U 777977,799979,1111151,3353333,5595559,5755559,7577777,9999991,33335333,55555553,55555559

%N Prime numbers consisting of only odd digits such that there is only one permutation of its digits that produces a prime number.

%t t2 = Select[Prime[Range[100000]], Intersection[{0, 2, 4, 6, 8}, Union[IntegerDigits[#]]] == {} &]; t = {}; Do[If[Length[Select[Table[FromDigits[k], {k, Permutations[IntegerDigits[p]]}], PrimeQ]] == 1, AppendTo[t, p]], {p, t2}]; t

%t edpQ[n_]:=Module[{idn=IntegerDigits[n]},AllTrue[idn,OddQ]&&Count[ FromDigits/@ Permutations[idn],_?PrimeQ]==1]; Select[Prime[ Range[ 332*10^4]],edpQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Nov 25 2018 *)

%Y Cf. A039986 (similar, but allowing even digits also).

%K nonn,base

%O 1,1

%A _T. D. Noe_, May 07 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 5 22:11 EDT 2020. Contains 336214 sequences. (Running on oeis4.)