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A068015
Gaps between non-twin primes.
1
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
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
KEYWORD
nonn
AUTHOR
Neil Fernandez, Mar 22 2002
STATUS
approved