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!)
 A110705 Numbers n such that "n 42's followed by 43" is prime. 2
 0, 1, 2, 3, 4, 7, 17, 24, 59, 199, 743, 2558, 4896, 5539, 6192, 10977, 27679 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Equivalently, a(n) generates primes of the form (100^(1+a(n)) - 1) * 42/99 + 1. - Mohsen Hozan, Jan 23 2015 LINKS MATHEMATICA t = 1; Do[ t = t*100 - 57; If[PrimeQ[t], Print[n]], {n, 0, 3000}] robinsonQ[n_] := PrimeQ[(100^(1 + n) - 1) * 42/99 + 1]; Select[Range[200], robinsonQ] (* Robert G. Wilson v, Jan 23 2015 *) PROG (PARI) t=1; for(n=0, 10^6, t=100*t-57; if(ispseudoprime(t), print1(n, ", "))); \\ Joerg Arndt, Nov 21 2014 (PFGW) ABC2 1+(100^(1+\$a)-1)*42/99 a: from 0 to 28000 \\ Charles R Greathouse IV, Mohsen Hozan, Jan 23 2015 CROSSREFS Cf. A110704, A254002. Sequence in context: A027362 A068194 A179985 * A139439 A119330 A084644 Adjacent sequences:  A110702 A110703 A110704 * A110706 A110707 A110708 KEYWORD nonn,base,more AUTHOR Ray Chandler, Aug 04 2005 EXTENSIONS a(13)-a(17) from Mohsen Hozan, Feb 10 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 May 31 02:51 EDT 2020. Contains 334747 sequences. (Running on oeis4.)