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 A145025 Numbers which are the average of two consecutive odd primes (A024675) together with primes which are the average of the previous prime and the following prime (A006562). 9
 4, 5, 6, 9, 12, 15, 18, 21, 26, 30, 34, 39, 42, 45, 50, 53, 56, 60, 64, 69, 72, 76, 81, 86, 93, 99, 102, 105, 108, 111, 120, 129, 134, 138, 144, 150, 154, 157, 160, 165, 170, 173, 176, 180, 186, 192, 195, 198, 205, 211, 217, 225, 228, 231, 236, 240, 246, 254, 257, 260 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers n such that prevprime(n) + nextprime(n) = 2n. - Wesley Ivan Hurt, May 13 2017 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 MAPLE Primes:= select(isprime, [seq(i, i=3..1000, 2)]): nprimes:= nops(Primes): A024675:= {seq((Primes[i]+Primes[i+1])/2, i=1..nprimes-1)}: L:= Primes[1..-3]+Primes[3..-1]: A006562:=zip((s, t) -> if 2*s=t then s else NULL fi, Primes[2..-2], L): sort(convert(convert(A006562, set) union A024675, list)); # Robert Israel, Nov 20 2016 MATHEMATICA Union[Select[Map[Mean@ {First@ #, Last@ #} &, Partition[#, 3, 1]], PrimeQ], Map[Mean, Partition[#, 2, 1]]] &@ Prime@ Range[2, 56] (* Michael De Vlieger, Jan 31 2019 *) PROG (PARI) for(n=2, 999, n-precprime(n-1)==nextprime(n+1)-n&&print1(n", ")) \\ M. F. Hasler, Jun 01 2013 CROSSREFS Equals A024675 U A006562. - M. F. Hasler, Jun 01 2013 Sequence in context: A003156 A192360 A115984 * A245236 A209122 A073263 Adjacent sequences:  A145022 A145023 A145024 * A145026 A145027 A145028 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Sep 29 2008 EXTENSIONS Entry revised by N. J. A. Sloane, Mar 24 2017, replacing old definition with definition from M. F. Hasler STATUS approved

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Last modified August 4 02:24 EDT 2021. Contains 346441 sequences. (Running on oeis4.)