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!)
A127441 Numbers n such that between n and n+sqrt(n) there are no primes. 2
3, 7, 8, 13, 23, 24, 31, 113, 114, 115, 116 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
If Oppermann's conjecture is true, then all terms are nonsquares. Data from A002386 and A005250 show that a(12) > 6787988999657777797 if it exists. Most likely there are no further terms. - Chai Wah Wu, Mar 08 2019
LINKS
MATHEMATICA
a = {}; Do[If[PrimePi[x + x^(1/2)] - PrimePi[x] == 0, AppendTo[a, x]], {x, 1, 249900000000000}]; a
PROG
(PARI) isok(n) = primepi(n+sqrtint(n)) == primepi(n); \\ Michel Marcus, Nov 07 2013
CROSSREFS
Sequence in context: A252496 A279517 A106474 * A067064 A093722 A309745
KEYWORD
nonn,more
AUTHOR
Artur Jasinski, Jan 14 2007
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 March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)