A129311 Numbers k such that 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)-1 and 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)+1 are twin primes with p(h) = h-th prime.

1, 185, 287, 296, 1372, 1959, 2531, 3630, 5393, 6332, 7210, 7315, 8108, 8258, 8794, 9340, 9989, 11270, 11706, 12213, 13494, 13710, 14246, 14402, 18188, 19010, 19075, 20179, 21394, 22483, 24256, 24309, 25070, 26284, 26634, 30578, 31799, 32351, 32652, 33390

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Giovanni Resta)

Example

6*2*3*5*7*11*13-1=180179 prime,  180179+2=180181 twin prime of 180179, so n(1)=1.

Mathematica

PrimePi[Part[#, 1, 1] & /@ FactorInteger /@  Select[Times @@@ Partition[ Prime[Range[5 10^4]], 6, 1], PrimeQ[6 # + 1] && PrimeQ[6 # - 1] &]] (* Giovanni Resta, Sep 16 2019 *)

Crossrefs

Cf. A129310, A129313.

Sequence in context: A157297 A156059 A244248 * A252272 A247529 A301991

Adjacent sequences: A129308 A129309 A129310 * A129312 A129313 A129314

Keyword

nonn

Author

Pierre CAMI, Apr 09 2007

Extensions

More terms from Giovanni Resta, Sep 16 2019

Status

approved