A031168 a(n) = prime(n+6) - prime(n).

15, 16, 18, 22, 20, 24, 24, 24, 24, 24, 28, 24, 26, 28, 26, 26, 24, 28, 30, 30, 30, 28, 26, 24, 30, 30, 34, 32, 40, 38, 30, 32, 30, 34, 30, 30, 34, 30, 30, 26, 32, 42, 36, 36, 36, 40, 30, 28, 30, 34, 36, 32, 36, 30, 26, 30, 38, 40, 36, 36, 48, 44, 40, 38, 40, 42, 36

Offset: 1

Author

Jeff Burch

Keywords

• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A001223, A031131, A031165, A031166, A031167, A031169, A031170, A031171, A031172.

Programs

Haskell

a031168 n = a031168_list !! (n-1)
a031168_list = zipWith (-) (drop 6 a000040_list) a000040_list
-- Reinhard Zumkeller, Aug 23 2015

Magma

[NthPrime(n+6)-NthPrime(n): n in [1..100] ]; // Vincenzo Librandi, Apr 23 2011

Maple

seq(ithprime(n+6)-ithprime(n), n=1..70);

Mathematica

a=6; t=Array[Prime,123]; Drop[t,a]-Drop[t,-a] (* Vladimir Joseph Stephan Orlovsky, Aug 13 2009 *)
Last[#]-First[#]&/@Partition[Prime[Range[80]],7,1] (* Harvey P. Dale, Jan 12 2012 *)

Extensions

Offset changed from 2 to 1, and a(1)=15 added, by Vincenzo Librandi, Apr 23 2011