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!)
 A060121 First solution mod p of x^3 = 2 for primes p such that only one solution exists. 6
 0, 2, 3, 7, 8, 16, 26, 5, 21, 18, 38, 49, 50, 16, 26, 6, 81, 54, 98, 70, 157, 161, 58, 147, 21, 86, 92, 197, 50, 249, 137, 184, 119, 45, 45, 261, 198, 61, 176, 143, 51, 103, 221, 72, 11, 219, 35, 86, 385, 384, 141, 143, 225, 92, 245, 533, 557, 473, 170, 375, 516 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Solutions mod p are represented by integers from 0 to p-1. For i > 1, i is a solution mod p of x^3 = 2 iff p is a prime factor of i^3-2 and p > i (cf. comment to A059940). i^3-2 has at most two prime factors > i. Hence i is a solution mod p of x^3 = 2 for at most two different p and therefore no integer occurs more than twice in this sequence. There are integers which do occur twice, e.g. 16, 21, 26 (cf. A060914). Moreover, no integer occurs more than twice in A060121, A060122, A060123 and A060124 taken together. LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA a(n) = first (only) solution mod p of x^3 = 2, where p is the n-th prime such that x^3 = 2 has only one solution mod p, i.e. p is the n-th term of A045309. EXAMPLE a(9) = 21, since 47 is the ninth term of A045309 and 21 is the only solution mod 47 of x^3 = 2. MAPLE Res:=0, 2: count:= 2: p:= 3: while count < 100 do p:= nextprime(p); if p mod 3 = 2 then count:= count+1; Res:= Res, numtheory:-mroot(2, 3, p); fi od: Res; # Robert Israel, Sep 12 2018 MATHEMATICA terms = 100; A045309 = Select[Prime[Range[2 terms]], Mod[#, 3] != 1&]; a[n_] := PowerMod[2, 1/3, A045309[[n]]]; Array[a, terms] (* Jean-François Alcover, Feb 27 2019 *) CROSSREFS Cf. A040028, A045309, A059940, A060914, A060122, A060123, A060124. Sequence in context: A076550 A062269 A244508 * A002964 A166966 A247843 Adjacent sequences: A060118 A060119 A060120 * A060122 A060123 A060124 KEYWORD nonn AUTHOR Klaus Brockhaus, Mar 02 2001 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 May 23 18:34 EDT 2024. Contains 372765 sequences. (Running on oeis4.)