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 A174258 Numbers n such that exactly one of 3*prime(n)-4 and 3*prime(n)+4 is prime. 1
 1, 4, 6, 7, 9, 10, 12, 13, 15, 16, 18, 19, 21, 26, 27, 28, 29, 34, 35, 37, 40, 41, 42, 45, 48, 49, 54, 57, 58, 59, 60, 61, 62, 66, 67, 70, 71, 73, 74, 76, 78, 82, 84, 85, 88, 92, 95, 101, 102, 103, 105, 108, 109, 113, 114, 115, 117, 120, 123, 124, 125, 126, 127, 130, 134 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE a(1)=1 because 3*prime(1)-4=2 is prime and 3*prime(1)+4=10 is composite; a(2)=4 because 3*prime(4)-4=17 is prime and 3*prime(4)+4=25 is composite. MATHEMATICA Select[Range[200], Total[Boole[PrimeQ[3Prime[#]+{4, -4}]]]==1&] (* Harvey P. Dale, May 08 2019 *) CROSSREFS Sequence in context: A095096 A179242 A104425 * A080746 A246362 A069909 Adjacent sequences:  A174255 A174256 A174257 * A174259 A174260 A174261 KEYWORD nonn,easy AUTHOR Juri-Stepan Gerasimov, Mar 14 2010 EXTENSIONS Corrected by Charles R Greathouse IV, Mar 19 2010 STATUS approved

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Last modified May 11 15:11 EDT 2021. Contains 343791 sequences. (Running on oeis4.)