This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A088228 Number of composite numbers between the smallest primes that surround n# and n#+n. n# = n primorial = product of primes <= n. 1
 1, 4, 6, 22, 22, 17, 47, 45, 79, 101, 138, 119, 71, 135, 173, 131, 167, 197, 189, 229, 175, 233, 285, 101, 353, 363, 335, 277, 485, 441, 385, 407, 1031, 519, 307, 363, 611, 477, 431, 381, 421, 605, 525, 1343, 605, 1229 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 LINKS Harvey P. Dale, Table of n, a(n) for n = 2..200 MATHEMATICA Count[#, _?CompositeQ]&/@(Module[{pr=Prime[Range[50]]}, Range[ NextPrime[ Last[#], -1]+1, NextPrime[Total[#]]-1]&/@Thread[{pr, Rest[ FoldList[ Times, 1, pr]]}]]) (* Harvey P. Dale, Aug 03 2014 *) PROG (PARI) primorialgaps(m) = { forprime(n=2, m, c=0; np=primorial(n); for(x=precprime(np), nextprime(np+n), if(!isprime(x), c++)); print1(c", ") ) } primorial(k) = { p=1; forprime(z=1, k, p*=z); return(p) } CROSSREFS Sequence in context: A227249 A002270 A286358 * A272309 A108636 A101143 Adjacent sequences:  A088225 A088226 A088227 * A088229 A088230 A088231 KEYWORD nonn AUTHOR Cino Hilliard, Nov 04 2003 STATUS approved

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

Last modified October 22 12:47 EDT 2019. Contains 328318 sequences. (Running on oeis4.)