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A266847
Primes p such that p+/-2, p+/-4 and p+/-6 are semiprimes.
1
6803, 52163, 67103, 116009, 155609, 196613, 242243, 277703, 523403, 706987, 764189, 973853, 1053863, 1307197, 1610333, 1823797, 1843687, 1995337, 2186603, 2487367, 2638747, 2875643, 2972663, 3032693, 3137399, 3179107, 3203243, 3209797, 3393809, 3454201, 3548033, 4302847, 4523093
OFFSET
1,1
EXAMPLE
a(1)=6803 because 6797=7*971, 6799=13*523, 6801=3*2267, 6805=5*1361, 6807=3*2269, 6809=11*619.
PROG
(PARI) lista(nn) = {forprime(p=7, nn, if (bigomega(p-6)==2 && bigomega(p+6)==2 && bigomega(p-4)==2 && bigomega(p+4)==2 && bigomega(p-2)==2 && bigomega(p+2)==2, print1(p, ", ")); ); } \\ Michel Marcus, Jan 07 2016
(Magma) IsSemiprime:=func< p | &+[ k[2]: k in Factorization(p)] eq 2 >; [p: p in PrimesInInterval(3, 4*10^6)| IsSemiprime(p+2) and IsSemiprime(p-2) and IsSemiprime(p+4) and IsSemiprime(p-4)and IsSemiprime(p+6) and IsSemiprime(p-6)]; // Vincenzo Librandi, Jan 07 2016
CROSSREFS
Subsequence of A266845 and A063643.
Sequence in context: A121106 A046515 A199996 * A345592 A345850 A132215
KEYWORD
nonn
AUTHOR
Zak Seidov, Jan 04 2016
EXTENSIONS
More terms from Michel Marcus, Jan 07 2016
STATUS
approved