A105469 Number of numbers of the form 6k+3 with prime(n) <= 6k+3 < prime(n+1).

0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 2, 1, 1, 0, 2, 0, 1, 1, 1, 1, 1, 0, 2, 0, 1, 0, 2, 2, 1, 0, 1, 1, 0, 2, 1, 1, 1, 0, 1, 1, 0, 2, 2, 1, 0, 1, 2, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 2, 0, 1, 1, 1, 1, 1, 0, 1, 2, 1, 1, 1, 1, 1, 2, 0, 3, 1, 2, 1, 1, 0, 1

Offset

1,30

Links

Table of n, a(n) for n=1..105.

Example

a(4)=1 because between prime(4)=7 and prime(5)=11 there is one number of the form 6k+3: 9.

Mathematica

f[n_] := Count[Table[Mod[k, 6], {k, Prime[n], Prime[n + 1] - 1}], 3]; Table[f[n], {n, 120}] (* Ray Chandler, Oct 17 2006 *)

Crossrefs

Sequence in context: A168261 A180997 A143439 * A257857 A339871 A276806

Adjacent sequences: A105466 A105467 A105468 * A105470 A105471 A105472

Keyword

easy,nonn

Author

Giovanni Teofilatto, May 02 2005

Extensions

Corrected and extended by Ray Chandler, Oct 17 2006

Status

approved