login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A048950 Base 3 Euler-Jacobi pseudoprimes. 4
121, 703, 1729, 1891, 2821, 3281, 7381, 8401, 8911, 10585, 12403, 15457, 15841, 16531, 18721, 19345, 23521, 24661, 28009, 29341, 31621, 41041, 44287, 46657, 47197, 49141, 50881, 52633, 55969, 63139, 63973, 74593, 75361, 79003, 82513 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Odd composite n with gcd(n,3)=1 and 3^((n-1)/2) == (3,n) (mod n) where (.,.) is the Jacobi symbol. - R. J. Mathar, Jul 15 2012
The base 5 Euler-Jacobi pseudoprimes are 781, 1541, 1729, 5461, 5611, 6601, 7499,... - R. J. Mathar, Jul 15 2012
LINKS
Eric Weisstein's World of Mathematics, Euler-Jacobi Pseudoprime.
MATHEMATICA
Select[Range[1, 10^5, 2], GCD[#, 3] == 1 && CompositeQ[#] && PowerMod[3, (# - 1)/2, #] == Mod[JacobiSymbol[3, #], #] &] (* Amiram Eldar, Jun 28 2019 *)
PROG
(PARI) is(n) = n%2==1 && gcd(n, 3)==1 && Mod(3, n)^((n-1)/2)==kronecker(3, n)
forcomposite(c=1, 83000, if(is(c), print1(c, ", "))) \\ Felix Fröhlich, Jul 15 2019
CROSSREFS
Cf. A047713 (base 2), A005935.
Sequence in context: A036306 A014749 A262051 * A329705 A020229 A141350
KEYWORD
nonn
AUTHOR
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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 10:31 EDT 2024. Contains 371240 sequences. (Running on oeis4.)