A129313 Numbers k such that 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*(k+5)*p(k+6)-1 and 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*(k+5)*p(k+6)+1 are twin primes with p(h) = h-th prime.

879, 979, 5555, 10950, 11728, 14485, 14809, 21716, 22117, 22933, 23371, 24473, 27514, 27597, 28475, 29581, 30548, 30694, 30887, 31128, 31783, 32197, 34016, 36539, 37491, 39277, 39430, 48555, 49347, 50596, 52602, 56284, 56473, 57482

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

PrimePi[Part[#, 1, 1] & /@ FactorInteger /@  Select[Times @@@ Partition[Prime[Range[6*10^4]], 7, 1], PrimeQ[6 # + 1] && PrimeQ[6 # - 1] &]] (* Amiram Eldar, Jan 26 2020 after Giovanni Resta at A129311 *)

Crossrefs

Cf. A129310, A129311.

Sequence in context: A208472 A093943 A252437 * A063051 A190030 A118799

Adjacent sequences: A129310 A129311 A129312 * A129314 A129315 A129316

Keyword

nonn

Author

Pierre CAMI, Apr 09 2007

Status

approved