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!)
A256736 Number of composites lying between successive pairs of primes, beginning with pair (3,5). Bisection of A046933. 2
1, 3, 3, 3, 1, 3, 3, 5, 5, 1, 3, 7, 1, 1, 13, 5, 9, 5, 3, 5, 9, 3, 11, 3, 3, 1, 5, 5, 5, 1, 13, 1, 13, 9, 3, 7, 5, 5, 3, 9, 9, 5, 5, 3, 3, 7, 7, 5, 1, 5, 5, 1, 9, 5, 5, 3, 11, 1, 5, 1, 3, 7, 7, 7, 5, 7, 3, 3, 9, 1, 1, 1, 13, 1, 13, 1, 19, 7, 7, 5, 13, 5, 7, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
[3,5] contains 4, so a(1)=4.
[7,11] contains 8,9,10, so a(2)=3.
For the third term in the sequence, use prime pair [13,17]. There are three composites between 13 and 17, thus the third term = 3.
MATHEMATICA
Table[Prime[n + 1] - Prime[n] - 1, {n, 2, 100, 2}] (* Hartmut F. W. Hoft, Apr 24 2015 *)
PROG
(PARI) a(n) = prime(2*n+1)-prime(2*n)-1; \\ Jinyuan Wang, Jul 09 2020
CROSSREFS
Complement of A256737 in regards to forming A046933.
Sequence in context: A167817 A153401 A181520 * A123073 A059289 A201277
KEYWORD
nonn
AUTHOR
Peter Woodward, Apr 09 2015
EXTENSIONS
Corrected and extended by Hartmut F. W. Hoft, Apr 24 2015
More terms from Robert G. Wilson v, May 03 2015
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 February 25 09:35 EST 2024. Contains 370313 sequences. (Running on oeis4.)