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A109982
Primes p such that index of p, the sum of p's digits and the number of p's digits are all primes.
2
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
OFFSET
1,1
LINKS
EXAMPLE
a(414) = 99551 because its index, 9551, the sum, 29 and number, 5, of digits are all primes.
MATHEMATICA
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 *)
CROSSREFS
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.
Sequence in context: A158205 A179446 A260269 * A128467 A238713 A132232
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Jul 06 2005
STATUS
approved