A354694 - OEIS

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A354694

Least Euler pseudoprime to base 2 through base prime(n).

341, 1729, 1729, 46657, 46657, 162401, 399001, 399001, 399001, 399001, 488881, 3057601, 3057601, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 17098369, 17098369, 17098369, 17098369, 17236801, 17236801

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OFFSET

1,1

COMMENTS

a(n) is coprime to A002110(n).

LINKS

Table of n, a(n) for n=1..31.

Eric Weisstein's World of Mathematics, Euler Pseudoprime.

PROG

(PARI) a(n) = my(b, m, p=factorback(primes(n))); forcomposite(k=9, oo, if(gcd(k, p)==1, b=2; while((m=Mod(b, k)^(k\2)) == 1 || m == k-1, b++); if(b>prime(n), return(k))));

CROSSREFS

Cf. A002110, A007324, A083876, A271221.

Sequence in context: A020230 A087716 A084653 * A143688 A086250 A285549

Adjacent sequences: A354691 A354692 A354693 * A354695 A354696 A354697

KEYWORD

nonn

AUTHOR

Jinyuan Wang, Jun 04 2022

STATUS

approved