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 A075177 Indices of additive primes - primes with prime sum-of-digits, see A046704. 6
 1, 2, 3, 4, 5, 9, 10, 13, 14, 15, 18, 19, 23, 24, 26, 30, 32, 33, 34, 36, 37, 40, 41, 43, 44, 45, 46, 48, 49, 50, 53, 56, 57, 60, 61, 64, 65, 66, 67, 68, 71, 72, 74, 75, 78, 79, 80, 82, 86, 87, 89, 90, 91, 93, 102, 105, 106, 108, 109, 110, 111, 116, 117, 118, 121, 124, 128 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS There are 107 additive primes among first 200 primes. There are 38455 additive primes among first 100000 primes. Additive primes are in A046704. LINKS Zak Seidov, Table of n, a(n) for n=1..4086, a(n)<10^4. FORMULA PrimePi[A046704(n)] A000040(a(n)) = A046704(n). EXAMPLE Prime(10)=29 is additive prime because 2+9=11 is prime. MATHEMATICA Map[PrimePi[ # ]&, Select[Prime[Range[200]], PrimeQ[Apply[ Plus, IntegerDigits[ # ]]]&] Flatten[Position[Prime[Range[150]], _?(PrimeQ[Total[IntegerDigits[#]]]&), {1}, Heads->False]] (* Harvey P. Dale, May 29 2013 *) PROG (Haskell) import Data.List (elemIndices) a075177 n = a075177_list !! (n-1) a075177_list = map (+ 1) \$    elemIndices 1 \$ map (a010051 . a007953) a000040_list -- Reinhard Zumkeller, Nov 13 2011 CROSSREFS Cf. A046704. Cf. A007953, A010051. Sequence in context: A246397 A015837 A262511 * A062096 A176008 A143827 Adjacent sequences:  A075174 A075175 A075176 * A075178 A075179 A075180 KEYWORD nonn,base AUTHOR Zak Seidov, Sep 06 2002 STATUS approved

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Last modified September 20 16:50 EDT 2021. Contains 347586 sequences. (Running on oeis4.)