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A109982
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Primes p such that index of p, the sum of p's digits and the number of p's digits are all primes.
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2
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11, 41, 67, 83, 157, 179, 191, 241, 283, 331, 353, 401, 461, 599, 739, 773, 797, 919, 991, 10079, 10169, 10433, 10457, 10589, 10631, 10723, 10853, 10909, 11311, 11447, 11867, 11953, 12097, 12143, 12301, 12457, 12479, 12503, 12547, 12763, 13003
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(414) = 99551 because its index, 9551, the sum, 29 and number, 5, of digits are all primes.
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MATHEMATICA
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Select[Prime[Range[200]], PrimeQ[Length[IntegerDigits[ # ]]]&&PrimeQ[Plus@@IntegerDigits[ # ]]&]
Select[Prime[Range[1600]], AllTrue[{PrimePi[#], Total[IntegerDigits[#]], IntegerLength[ #]}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Sep 15 2019 *)
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CROSSREFS
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Cf. A046704 Additive primes: sum of digits is a prime, A088136 Primes such that sum of first and last digits is prime, A109981 Primes such that the sum of digits and the number of digits are primes.
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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