The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A215237 Least number k for which primepi(prime(k+1)/2) - primepi(prime(k)/2) = n. 3
 1, 2, 30, 259, 429, 4612, 26466, 88110, 31545, 104071, 2775456, 14614604, 15793779, 164082567, 476853784, 495207013, 3613011290, 9032608100, 69827848342 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS See A215238 and A215239 for prime(a(n)) and the next prime. Equivalently stated, a(n) is least k such that there are exactly n primes between prime(k)/2 and prime(k+1)/2. - Peter Munn, May 20 2019 LINKS EXAMPLE For n = 2, the consecutive primes are 113 and 127; there are two primes between 56.5 and 63.5.  For n = 3, the consecutive primes are 1637 and 1657; there are three primes between 818.5 and 828.5. MATHEMATICA t = Table[PrimePi[Prime[n+1]/2] - PrimePi[Prime[n]/2], {n, 100000}]; Flatten[Table[Position[t, n, 1, 1], {n, 0, 8}]] CROSSREFS Cf. A217564, A215238, A215239. Sequence in context: A007030 A157054 A092355 * A189103 A300423 A300685 Adjacent sequences:  A215234 A215235 A215236 * A215238 A215239 A215240 KEYWORD nonn,more,hard AUTHOR T. D. Noe, Oct 09 2012 EXTENSIONS a(14)-a(18) from Donovan Johnson, Oct 13 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.

Last modified August 9 18:55 EDT 2022. Contains 356026 sequences. (Running on oeis4.)