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!)
 A108830 Primes such that the outer 2 digits are n and n-1 and all inner digits are 2, where 0 < n < 9. 0
 827, 2221, 42223, 4222222223, 42222222223, 222222222222222221, 822222222222222222227, 42222222222222222222222222222223, 8222222222222222222222222222222227, 822222222222222222222222222222222222222222222222222222222222227 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS MATHEMATICA Sort[Select[Flatten[Table[FromDigits[Join[{n}, PadRight[{}, i, 2], {n-1}]], {n, 2, 8, 2}, {i, 70}]], PrimeQ]] (* Harvey P. Dale, Dec 05 2015 *) PROG (PARI) n10np1(n, d) = { local(x, y, k); for(x=1, n, for(k=1, 8, y=10^(x+1)*k+floor(10^x*d/9)*10+k-1; if(isprime(y), print1(y", ")) ) ) } CROSSREFS Sequence in context: A143799 A046496 A102350 * A341272 A340115 A134726 Adjacent sequences:  A108827 A108828 A108829 * A108831 A108832 A108833 KEYWORD easy,nonn,base AUTHOR Cino Hilliard, Jul 11 2005 EXTENSIONS One more term (a(10)) from Harvey P. Dale, Dec 05 2015 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 June 21 19:12 EDT 2021. Contains 345365 sequences. (Running on oeis4.)