A060267 Difference between 2 closest primes surrounding 2n.

2, 2, 4, 4, 2, 4, 4, 2, 4, 4, 6, 6, 6, 2, 6, 6, 6, 4, 4, 2, 4, 4, 6, 6, 6, 6, 6, 6, 2, 6, 6, 6, 4, 4, 2, 6, 6, 6, 4, 4, 6, 6, 6, 8, 8, 8, 8, 4, 4, 2, 4, 4, 2, 4, 4, 14, 14, 14, 14, 14, 14, 14, 4, 4, 6, 6, 6, 2, 10, 10, 10, 10, 10, 2, 6, 6, 6, 6, 6, 6, 4, 4, 6, 6, 6, 6, 6, 6, 2, 10, 10, 10, 10, 10, 2, 4

Offset

2,1

Links

Michael De Vlieger, Table of n, a(n) for n = 2..10000

Example

a(3) = 2 because the closest primes to 2*3 = 6 are (5,7) and the difference between these is 2. - Michael De Vlieger, Nov 02 2017

Maple

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

Mathematica

Array[Subtract @@ NextPrime[#, {1, -1}] &[2 #] &, 96, 2] (* Michael De Vlieger, Nov 02 2017 *)
NextPrime[#]-NextPrime[#, -1]&/@(2*Range[2, 100]) (* Harvey P. Dale, Nov 07 2017 *)

Prog

(PARI) a(n) = nextprime(2*n+1) - precprime(2*n-1); \\ Michel Marcus, Sep 16 2020

Crossrefs

Cf. A020482, A049653, A060264, A060265, A060266, A060268.

Sequence in context: A049116 A065176 A368558 * A214516 A352502 A238004

Adjacent sequences: A060264 A060265 A060266 * A060268 A060269 A060270

Keyword

nonn

Author

Labos Elemer, Mar 23 2001

Status

approved