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 A099349 Primes p such that p+nextprime(p) is the arithmetic mean of a pair of twin primes. 20
 5, 7, 13, 19, 29, 67, 97, 113, 229, 293, 307, 401, 409, 439, 613, 643, 659, 709, 739, 809, 829, 859, 937, 1039, 1051, 1327, 1483, 1663, 1693, 1879, 1999, 2039, 2113, 2129, 2239, 2251, 2549, 2633, 2707, 2749, 2753, 2819, 3041, 3089, 3137, 3221, 3271, 3329 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence (obviously) uses the "strictly larger" variant 2 (A151800) of the nextprime() function, rather than A007918. - M. F. Hasler, Sep 09 2015 LINKS EXAMPLE 19+23=42 sum of consecutive primes and also arithmetic mean of twin primes 41 and 43. MATHEMATICA okQ[p_] := Module[{s = p + NextPrime[p]}, PrimeQ[s - 1] && PrimeQ[s + 1]]; Select[Prime[Range[1000]], okQ] (* Zak Seidov, Apr 10 2011 *) PROG (MAGMA) [n: n in PrimesUpTo(3330) | IsPrime(n+NextPrime(n)-1) and IsPrime(n+NextPrime(n)+1)];  // Bruno Berselli, Apr 10 2011 (PARI) is(n)=if(isprime(n), n+=nextprime(n+1); isprime(n-1) && isprime(n+1), 0) \\ Charles R Greathouse IV, Jul 01 2013 CROSSREFS Cf. A151800, A007918. Sequence in context: A045443 A153116 A227420 * A167464 A280266 A243457 Adjacent sequences:  A099346 A099347 A099348 * A099350 A099351 A099352 KEYWORD nonn,easy AUTHOR Labos Elemer, Nov 17 2004 EXTENSIONS Corrected and edited by Zak Seidov, Apr 10 2011 STATUS approved

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