A068015 Gaps between non-twin primes.

21, 14, 10, 6, 14, 12, 4, 6, 8, 16, 14, 4, 26, 6, 4, 6, 38, 12, 10, 18, 6, 6, 14, 16, 14, 10, 14, 6, 16, 6, 8, 6, 6, 4, 6, 8, 4, 8, 30, 4, 6, 8, 10, 12, 8, 4, 8, 4, 6, 32, 6, 10, 6, 14, 10, 6, 14, 6, 18, 16, 6, 20, 4, 6, 8, 10, 8, 10

Offset

1,1

Comments

a(n) >= 4. - Zak Seidov, May 11 2015

Links

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

Formula

a(n) = A007510(n+1) - A007510(n). - Zak Seidov, May 11 2015

Example

The first primes that are not 2 less than or 2 greater than another prime are 2, 23, 37,... (A007510). The second gap is 37-23=14, so a(2)=14.

Mathematica

ntpg[n_]:=Module[{prn=Prime[Range[n]], tp}, tp=Union[Flatten[Select[ Partition[prn, 2, 1], Last[#]- First[#] ==2&]]]; Differences[Complement[ prn, tp]]]; ntpg[200] (* Harvey P. Dale, Apr 09 2012 *)

Crossrefs

Cf. A007510.

Sequence in context: A307312 A120742 A118296 * A040422 A214037 A321281

Adjacent sequences: A068012 A068013 A068014 * A068016 A068017 A068018

Keyword

nonn

Author

Neil Fernandez, Mar 22 2002

Status

approved