A007324 Least number for which Solovay-Strassen primality test on bases < prime(n) fails.

9, 561, 1729, 1729, 399001, 399001, 1857241, 1857241, 6189121, 14469841, 14469841, 14469841

Offset: 1

Author

N. J. A. Sloane, Eric Bach (bach(AT)cs.wisc.edu)

Keywords

• nonn
• more

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Wikipedia, Solovay-Strassen primality test

Crossrefs

Cf. A083876, A271221, A329726.

Programs

PARI

a(n) = my(b, p=factorback(primes(n-1))); forcomposite(k=9, oo, if(gcd(k, p)==1, b=2; while(Mod(b, k)^(k\2) == kronecker(b, k), b++); if(b>=prime(n), return(k)))); \\ Jinyuan Wang, Jun 04 2022

Extensions

Offset changed to 1 and a(1) corrected by Jinyuan Wang, Jun 04 2022