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

1,6

Links

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

Formula

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

Example

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

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 *)

Crossrefs

Cf. A001223, A027833.

Sequence in context: A220504 A087569 A341509 * A001442 A226952 A158285

Adjacent sequences: A048611 A048612 A048613 * A048615 A048616 A048617

Keyword

nonn,easy

Author

Den Roussel (DenRoussel(AT)webtv.net)

Extensions

Corrected and extended by Labos Elemer, Mar 23 2000

Status

approved