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 A125001 Non-insertable primes: primes with property that no matter where you insert (or prepend or append) a digit you get a composite number (except for prepending a zero). 2

%I

%S 369293,3823867,5364431,5409259,7904521,8309369,9387527,9510341,

%T 22038829,27195601,28653263,38696543,39091441,39113161,43744697,

%U 45095839,45937109,48296921,48694231,49085093,49106677,50791927

%N Non-insertable primes: primes with property that no matter where you insert (or prepend or append) a digit you get a composite number (except for prepending a zero).

%C Is the sequence infinite? - _Zak Seidov_, Nov 14 2014

%H David W. Wilson and Zak Seidov, <a href="/A125001/b125001.txt">Table of n, a(n) for n = 1..3000</a>

%H Jeremiah T. Southwick, <a href="https://scholarcommons.sc.edu/etd/5879/">Two Inquiries Related to the Digits of Prime Numbers</a>, Ph. D. Dissertation, University of South Carolina (2020).

%e 369293 is a member because all of 1369293, 2369293, 3369293, ..., 3069293, 3169293, ..., 3692930, ..., 3692939 are composite.

%t nipQ[x_]:=Module[{id=IntegerDigits[x],len},len=Length[id];AllTrue[ Select[ Flatten[Table[FromDigits[Insert[id,n,i]],{i,len+1},{n,0,9}],1],#!=x&], CompositeQ]]; Select[ Prime[Range[3050000]],nipQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Apr 12 2018 *)

%K nonn,base

%O 1,1

%A _David W. Wilson_, Jan 08 2007

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Last modified May 25 20:09 EDT 2022. Contains 354071 sequences. (Running on oeis4.)