A048614 Number of primes between successive pairs of twin primes.

0, 0, 0, 1, 1, 2, 1, 4, 0, 3, 0, 4, 0, 0, 2, 1, 3, 1, 2, 3, 10, 0, 4, 7, 4, 3, 2, 1, 2, 18, 0, 0, 2, 2, 17, 0, 1, 0, 2, 6, 9, 3, 1, 1, 1, 8, 3, 2, 0, 15, 1, 4, 1, 1, 7, 7, 0, 4, 0, 4, 3, 4, 0, 1, 0, 1, 7, 2, 5, 1, 5, 18, 2, 5, 4, 3, 1, 5, 1, 18, 0, 12, 2, 8, 0, 1, 4, 2, 0, 0, 5, 0, 4, 1, 1, 1, 9, 10, 4, 2, 6

Offset: 1

Author

Den Roussel (DenRoussel(AT)webtv.net)

Keywords

• nonn
• easy

Examples

			a(8)= 4 because between the 8th and 9th pairs of twins there are 4 primes: (71,73) 79 83 89 97 (101,103).
		

Links

• T. D. Noe, Table of n, a(n) for n=1..10000

Crossrefs

Cf. A001223, A027833.

Programs

Mathematica

t1=Select[Prime[Range[3,542]],PrimeQ[#+2]&]; Prepend[Table[PrimePi[t1[[i+1]]]-PrimePi[t1[[i]]]-2,{i,1,Length[t1]-1}],0] (* Jayanta Basu, May 26 2013 *)

Formula

a(n) = A027833(n)-2 for n>1. - T. D. Noe, Feb 28 2007

Extensions

Corrected and extended by Labos Elemer, Mar 23 2000