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!)
 A099077 Numbers n such that pi(1).pi(2) ... pi(n-1).pi(n) is prime (dot between numbers means concatenation). 3
 5, 25, 2232, 4560 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Number of digits of primes corresponding to the four known terms of this sequence are respectively 4,24,6127,13111. Next term is greater than 10250 and the prime corresponding to the next term has more than 32500 digits. LINKS C. Rivera, Primes by Listing, The Prime Puzzles & Problems connection. Eric Weisstein's World of Mathematics, Integer Sequence Primes EXAMPLE 5 is in the sequence because pi(1).pi(2).pi(3).pi(4).pi(5)=1223 is prime. CROSSREFS Cf. A046035, A099078, A099079, A099080. Sequence in context: A039780 A328124 A033981 * A137113 A137115 A060063 Adjacent sequences:  A099074 A099075 A099076 * A099078 A099079 A099080 KEYWORD base,more,nonn AUTHOR Farideh Firoozbakht, Oct 23 2004 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 15:04 EST 2019. Contains 329877 sequences. (Running on oeis4.)