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A087368
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Prime-indexed primes (PIPs) whose digits are all primes.
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2
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3, 5, 277, 353, 773, 3733, 5557, 7523, 7753, 25357, 25733, 27733, 32233, 32323, 32533, 37273, 53233, 53353, 53377, 53777, 55733, 72337, 72727, 73757, 77377, 77557, 232523, 272333, 275773, 322727, 327553, 327757, 333233, 352357, 353527
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OFFSET
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1,1
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COMMENTS
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Chances are these numbers are infinite since PIPs are infinite.
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LINKS
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EXAMPLE
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59 is prime, the 59th prime is 277, and 2 and 7 are primes.
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MATHEMATICA
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Select[Flatten[Table[FromDigits /@ Tuples[Prime[Range[4]], k], {k, 1, 6}]], PrimeQ[#] && PrimeQ[PrimePi[#]] &] (* Amiram Eldar, Jul 08 2024 *)
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PROG
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(PARI) pip(n) = { for(x=1, n, flag=1; y=prime(prime(x)); y2=y; for(j=1, length(Str(y)), r = y%10; if(!isprime(r), flag=0); y = floor(y/10); ); if(flag, print1(y2", ")); ) }
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CROSSREFS
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KEYWORD
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easy,nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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