The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A204099 Number of integers between successive twin prime pairs. 5
0, 3, 3, 9, 9, 15, 9, 27, 3, 27, 9, 27, 9, 3, 27, 9, 27, 9, 27, 33, 69, 9, 27, 57, 45, 27, 15, 21, 15, 147, 9, 3, 27, 21, 135, 9, 15, 9, 27, 57, 75, 45, 9, 9, 15, 105, 21, 27, 3, 117, 9, 45, 27, 21, 63, 81, 3, 51, 15, 45, 27, 51, 3, 21, 15, 9, 93, 27, 39 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n) is divisible by 3.
LINKS
FORMULA
a(n) = A167132(n) - 1.
a(n) = A063091(n+1) - A063091(n) - 3.
EXAMPLE
a(1) = 0 because (3,5) is adjacent to (5,7); a(2) = 3 because the numbers 8, 9 and 10 are between (5,7) and (11,13), ...
MAPLE
T:=array(1..100, 1..2):k:=0:for n from 1 to 1000 do:p1:=ithprime(n):p2:=ithprime(n+1):if p2-p1 = 2 then k:=k+1:T[k, 1]:=p1:T[k, 2]:=p2:else fi:od: for p from 2 to k do:x:= T[p+1, 1]- T[p, 2]: printf(`%d, `, x-1):od:
MATHEMATICA
Module[{tr=Transpose[Select[Partition[Prime[Range[450]], 2, 1], #[[2]]- #[[1]] == 2&]], fir, las}, fir=Rest[tr[[1]]]; las=Most[tr[[2]]]; Flatten[Abs[ Differences/@ Thread[{fir, las}]]]-1/.{-1->0}] (* Harvey P. Dale, Jun 11 2014 *)
CROSSREFS
Sequence in context: A098355 A183429 A107443 * A062234 A168329 A161828
KEYWORD
nonn
AUTHOR
Michel Lagneau, Jan 10 2012
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 16 15:04 EDT 2024. Contains 373430 sequences. (Running on oeis4.)