The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A103783 Primes of the form primorial P(k)*n-1 with minimal n, n>0, k>=2. 4
 5, 29, 419, 2309, 30029, 1021019, 19399379, 669278609, 38818159379, 601681470389, 14841476269619, 304250263527209, 235489703970060539, 1844669347765474229, 228124109340330313109, 24995884552004764307909 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Weak conjecture: sequence is defined for all k>=2; strong conjecture: n<(prime(k))^2; Smallest prime p such that the prime factorization of p+1 contains the first n+1 primes. - R. J. Mathar, Jul 03 2012 LINKS EXAMPLE P(2)*1-1=5 is prime, so a(2)=5; P(9)*3-1=669278609 is prime, so a(9)=669278609; MATHEMATICA nmax = 2^2048; npd = 2; n = 2; npd = npd*Prime[n]; While[npd < nmax, tt = 1; cp = npd*tt - 1; While[(tt <= (Prime[n])^2) && (! (PrimeQ[cp])), tt = tt + 1; cp = npd*tt - 1]; Print[cp]; n = n + 1; npd = npd*Prime[n]] CROSSREFS Cf. A002110, A103515, A103782, A073917, A214089. Sequence in context: A216027 A087899 A202759 * A103515 A198054 A202758 Adjacent sequences:  A103780 A103781 A103782 * A103784 A103785 A103786 KEYWORD nonn AUTHOR Lei Zhou, Feb 15 2005 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 May 5 23:41 EDT 2021. Contains 343579 sequences. (Running on oeis4.)