The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A095967 Numbers n such that r3(k) * 2^n + 1 is prime, where r3() = A002277 and k is the number of decimal digits of 2^n. 0
 1, 2, 6, 9, 20, 46, 58, 64, 69, 110, 158, 178, 186, 268, 424, 624, 641, 1236, 1593, 2264, 2870, 5797, 7518, 7688, 9300 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(1) through a(25) have been proved to be prime with WinPFGW. a(25) has 5600 digits. No more terms up to 12800. Results were computed using the PrimeFormGW (PFGW) primality-testing program. - Hugo Pfoertner, Nov 14 2019 LINKS Table of n, a(n) for n=1..25. EXAMPLE a(4)=9 because 333 * 2^9 + 1 = 170497, a prime. CROSSREFS Sequence in context: A265016 A279897 A336131 * A316429 A337639 A047161 Adjacent sequences: A095964 A095965 A095966 * A095968 A095969 A095970 KEYWORD more,nonn,base AUTHOR Jason Earls, Jul 15 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 12 23:30 EDT 2024. Contains 373362 sequences. (Running on oeis4.)