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!)
A196128 Largest prime p[i] such that p[i]+p[i+1]+...+p[i+n-1] <= primorial(n) = A002110(n). 3
2, 2, 5, 43, 449, 4987, 72901, 1212427, 24787981, 646969237, 18232771699, 618394844407, 23403866424979, 934482952261687, 40992652172565871, 2036822404824377491, 113103550009071331379, 6516021186633720609839, 413595871109487739782749, 27897041506334948048370371 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
It is not known whether there is n (necessarily even) such that p[i]+p[i+1]+...+p[i+n-1] = primorial(n) for some p[i].
LINKS
J. M. Bergot, C. Rivera (Ed.), Problem 56.  p1*p2*…*pk = q1+q2+…+qk, on primepuzzle.net.
PROG
(PARI) A196128(k)={my(P=A002110(k), S=precprime(P\k), p=S, q=S); for(n=1, k, S+=if(S*k>P*n, p=precprime(p-1), q=nextprime(q+1))); p}
CROSSREFS
Sequence in context: A282706 A301346 A020549 * A227575 A114715 A270750
KEYWORD
nonn
AUTHOR
M. F. Hasler, Sep 28 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 March 29 11:14 EDT 2024. Contains 371278 sequences. (Running on oeis4.)