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 A064402 Numbers n such that prime(n)+n is a prime, where prime(n) denotes the n-th prime number. 19
 1, 2, 4, 6, 18, 22, 24, 26, 32, 34, 42, 48, 66, 70, 72, 82, 92, 96, 98, 100, 102, 104, 106, 108, 114, 116, 126, 130, 144, 150, 152, 158, 172, 180, 200, 202, 204, 206, 218, 222, 228, 236, 270, 282, 290, 300, 312, 322, 324, 328, 330, 350, 352, 356, 362, 378, 384 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = order among the primes of A061067(n). Except for the first one all terms are even. Conjecture: First differences include all even integers. - Zak Seidov, Nov 10 2013 LINKS Harry J. Smith, Table of n, a(n) for n=1..1000 FORMULA a(n) = A061068(n) - A061067(n-1). A014688(a(n)) = A061068(n). - Zak Seidov, Nov 10 2013 MATHEMATICA Select[ Range[ 400 ], PrimeQ[ Prime[ # ] + # ] & ] PROG (PARI) { n=0; for (m=1, 10^9, if (isprime(prime(m) + m), write("b064402.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 13 2009 (MAGMA) [n: n in [0..500]| IsPrime(NthPrime(n) +n)]; // Vincenzo Librandi, Apr 06 2011 CROSSREFS Cf. A061067, A061068, A064269. Sequence in context: A074131 A335038 A019464 * A268577 A075229 A242765 Adjacent sequences:  A064399 A064400 A064401 * A064403 A064404 A064405 KEYWORD nonn AUTHOR Robert G. Wilson v, Sep 28 2001 EXTENSIONS Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, Jun 08 2007 STATUS approved

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Last modified August 5 00:15 EDT 2021. Contains 346456 sequences. (Running on oeis4.)