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 A278138 Primes p such that p+2, 3*p+2 and 3*p+8 are also primes. 1
 3, 5, 17, 197, 1427, 1667, 2087, 4157, 4217, 8387, 8597, 10037, 11117, 11717, 15287, 17417, 20147, 25847, 29207, 33347, 33827, 34847, 35897, 36527, 47657, 56237, 57527, 60257, 63197, 63587, 69497, 75167, 77477, 89657, 93887, 96797, 99347, 99527, 100547 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS If k = (a(n)+2)*(3*a(n)+2), then A000203(k) = A000203(k-A000005(k)), see Robert Israel's comment at A277273. LINKS Iain Fox, Table of n, a(n) for n = 1..10000 (first 4356 terms from Robert Israel) MAPLE select(p -> isprime(3*p+8) and isprime(3*p+2) and isprime(p+2) and isprime(p), [3, seq(i, i=5..10^6, 6)]); # Robert Israel, Nov 23 2016 MATHEMATICA Select[Prime[Range[10000]], Union[PrimeQ/@{# + 2, 3 # + 2, 3 # + 8}] == {True}&] PROG (MATLAB) P = primes(10^6); P1 = intersect(P, P-2); P1 = intersect(P1, (P-2)/3); P1 = intersect(P1, (P-8)/3) % Robert Israel, Nov 23 2016 (MAGMA) [p: p in PrimesUpTo(100000) | IsPrime(p+2) and IsPrime(3*p+2) and IsPrime(3*p+8)]; // Vincenzo Librandi, Nov 23 2016 (PARI) isok(p) = isprime(p) && isprime(p+2) && isprime(3*p+2) && isprime(3*p+8); \\ Michel Marcus, Dec 17 2017 CROSSREFS Cf. A000040, A277273. Subsequence of A001359. Sequence in context: A083213 A171271 A056826 * A273870 A272060 A058910 Adjacent sequences:  A278135 A278136 A278137 * A278139 A278140 A278141 KEYWORD nonn,easy AUTHOR Ivan N. Ianakiev, Nov 23 2016 STATUS approved

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Last modified April 26 12:00 EDT 2019. Contains 322472 sequences. (Running on oeis4.)