A076504 Numbers k such that (k-1, k+1) and (k/2-1, k/2+1) are both pairs of twin primes.

12, 60, 1320, 1620, 4260, 5100, 6660, 6780, 11700, 12540, 21060, 66360, 83220, 88260, 107100, 110880, 114660, 127680, 130200, 140760, 141960, 144540, 148200, 149520, 157560, 161340, 163860, 175080, 186480, 204600, 230940, 249540

Offset

1,1

Comments

Terms after the first are multiples of 60. - Marc Morgenegg, Apr 19 2016

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = 2*A066388(n).

Mathematica

Select[Mean /@ Select[Partition[Prime[Range[30000]], 2, 1], Last[#] - First[#] == 2 &], And @@ PrimeQ[#/2 + {1, -1}] &] (* Harvey P. Dale, Jan 23 2014 *)

Crossrefs

Cf. A066388.

Sequence in context: A056378 A231026 A333969 * A232700 A354882 A044150

Adjacent sequences: A076501 A076502 A076503 * A076505 A076506 A076507

Keyword

nonn

Author

Eric W. Weisstein, Oct 15 2002

Extensions

Definition corrected by Jaroslav Krizek, Apr 12 2009

Status

approved