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!)
A164266 The count of primes between the n-th and (n+1)-st perfect number. 0
6, 85, 928, 2062427, 391549471, 5192879231 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = A000720(A000396(n+1)) - A000720(A000396(n)).
EXAMPLE
a(1)=6 counts the 6 primes 7, 11, 13, 17, 19 and 23 between 6 and 28.
a(2)=85 counts the 85 primes 29, 31, ..., 487, 491 between 28 and 496.
MATHEMATICA
PrimePi[Last[#]]-PrimePi[First[#]]&/@(Partition[(# (#+1))/2&/@ Select[ 2^Range[30]-1, PrimeQ], 2, 1]) (* Harvey P. Dale, Dec 27 2011 *)
CROSSREFS
Sequence in context: A284522 A167252 A290011 * A136597 A064329 A187740
KEYWORD
nonn,hard
AUTHOR
EXTENSIONS
Edited by R. J. Mathar, Aug 26 2009
More terms from Harvey P. Dale, Dec 27 2011
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 May 23 01:37 EDT 2024. Contains 372758 sequences. (Running on oeis4.)