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A274506
Primes one less than the sum over a pair of prime numbers that differ by 8.
1
13, 17, 29, 53, 113, 149, 269, 353, 389, 809, 1193, 1373, 1409, 1493, 1973, 2069, 2129, 2333, 2393, 2753, 2909, 2969, 3209, 4013, 4493, 4673, 5333, 5693, 6029, 6089, 6449, 6653, 7253, 7529, 7829, 7853, 8429, 8513, 9173, 9293, 10889, 10949, 11393, 11489, 11633, 12413, 12713, 12953, 13049, 13313, 14249, 14969
OFFSET
1,1
COMMENTS
Any prime p in this sequence is such that p = (p-7)/2 + (p+9)/2 - 1, where (p-7)/2 and (p+9)/2 are also primes and they differ by 8.
EXAMPLE
13 = 3 + 11 - 1. Note that, (13-7)/2 = 3 and (13+9)/2 = 11 and the prime pairs 3 and 11 differ by 8.
17 = 5 + 13 - 1. Note that, (17-7)/2 = 5 and (17+9)/2 = 13 and the prime pairs 5 and 13 differ by 8.
MATHEMATICA
Select[2 Select[Prime@ Range@ 1100, PrimeQ[# + 8] &] + 7, PrimeQ] (* Michael De Vlieger, Jun 26 2016 *)
PROG
(PARI) lista(nn) = forprime(p=3, nn, if (isprime((p-7)/2) && isprime((p+9)/2), print1(p, ", ")); ); \\ Michel Marcus, Jun 25 2016
(Perl) use ntheory ":all"; say for grep{is_prime($_)} map { $_+$_+8-1 } sieve_prime_cluster(1, 5e7, 8); # Dana Jacobsen, Apr 27 2017
CROSSREFS
Sequence in context: A283407 A283358 A033210 * A107159 A138375 A180526
KEYWORD
nonn
AUTHOR
STATUS
approved