This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A228727 Smallest prime of the form k*prime(n) + prime(k*n). 1
 7, 13, 23, 131, 179, 229, 283, 337, 107, 641, 317, 163, 643, 193, 1949, 523, 257, 2053, 1021, 1933, 2477, 773, 811, 401, 929, 6379, 457, 6197, 5701, 1747, 547, 1949, 1291, 2083, 647, 661, 2341, 709, 1579, 2549, 2633, 1721, 4909, 2851, 857, 877, 5441, 4441 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes of the form 2*prime(n) + prime(2*n): 7, 13, 23, 107, 163, 193, 257, 401, 457, 547, 647, 661, 709, 857, 877, 1201,... LINKS EXAMPLE a(1)=7 because 7 is prime and 2*prime(1) + prime(2*1) = 4 + 3 = 7. a(2) = 13 because 13 is prime and 2*prime(2) + prime(2*2) = 6 + 7 = 13. MATHEMATICA Table[k = 1; While[p = k*Prime[n] + Prime[k*n]; ! PrimeQ[p], k++]; p, {n, 100}] (* T. D. Noe, Sep 03 2013 *) CROSSREFS Cf. A095304. Sequence in context: A075642 A316118 A265766 * A286916 A032690 A188557 Adjacent sequences:  A228724 A228725 A228726 * A228728 A228729 A228730 KEYWORD nonn AUTHOR Irina Gerasimova, Aug 31 2013, Sep 04 2013 EXTENSIONS Corrected by R. J. Mathar, Sep 02 2013 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 December 9 00:32 EST 2019. Contains 329871 sequences. (Running on oeis4.)