A060271 Difference between smallest prime following and largest prime preceding 2*(n-th prime).

2, 4, 4, 4, 6, 6, 4, 4, 6, 6, 6, 4, 6, 8, 4, 14, 14, 6, 10, 10, 6, 4, 6, 4, 12, 12, 12, 12, 4, 6, 6, 6, 4, 14, 14, 4, 14, 6, 10, 6, 8, 4, 6, 8, 4, 10, 6, 8, 4, 4, 12, 8, 4, 12, 18, 18, 6, 10, 6, 6, 10, 4, 12, 12, 10, 12, 4, 10, 10, 8, 10, 6, 8, 4, 8, 14, 10, 12, 10, 10, 14, 4, 14, 4, 4, 20, 8

Offset

2,1

Links

Table of n, a(n) for n=2..88.

Example

n=1: p(1)=2, 2p(1)=4 is between 3 and 5, their difference is 2=a(1); n=6: p(6)=13, 2p(6)=26 is between 23 and 29 and their difference is 6=a(6).

Maple

with(numtheory): [seq(nextprime(2*ithprime(j))-prevprime(2*ithprime(j)), j=2...256)];

Mathematica

dsplp[n_]:=Module[{np=2Prime[n]}, NextPrime[np]-NextPrime[np, -1]]; Array[ dsplp, 90, 2] (* Harvey P. Dale, Mar 20 2013 *)

Crossrefs

Cf. A059786-A059790, A013633, A058043, A058249, A058044, A060267, A001223.

Sequence in context: A278481 A084291 A258573 * A073806 A060849 A130819

Adjacent sequences: A060268 A060269 A060270 * A060272 A060273 A060274

Keyword

nonn

Author

Labos Elemer, Mar 23 2001

Status

approved