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%I #13 Mar 30 2012 18:38:31
%S 15,28,35,39,51,52,55,63,66,70,75,76,87,95,99,111,112,115,119,123,124,
%T 130,135,143,147,148,154,155,159,171,172,176,183,186,187,190,195,196,
%U 203,207,208,215,219,232,235,238,244,246,255,267,268,275,276,279,280,286,287,291,292,295,299
%N Numbers n from A181780 that are not in A181781.
%C Numbers that are Fermat pseudoprimes to some base a (2<=a<=n-2) not Euler pseudoprimes to any base a (2<=a<=n-2).
%e 4^(15-1) == 1 (mod 15), but 4^((15-1)/2) == 4 (mod 15)
%o (PARI)
%o fsp(n)=
%o { /* whether n is Fermat pseudoprime to any base a where 2<=a<=n-2 */
%o for (a=2,n-2,
%o if ( gcd(a,n)!=1, next() );
%o if ( (Mod(a,n))^(n-1)==+1, return(1) )
%o );
%o return(0);
%o }
%o esp(n)=
%o { /* whether n is Euler pseudoprime to any base a where 2<=a<=n-2 */
%o local(w);
%o if ( n%2==0, return(0) );
%o for (a=2,n-2,
%o if ( gcd(a,n)!=1, next() );
%o w = abs(component((Mod(a,n))^((n-1)/2),2));
%o if ( (w==1) || (w==n-1), return(1) )
%o );
%o return(0);
%o }
%o for(n=3,300, if(isprime(n),next()); if( fsp(n) && (!esp(n)) , print1(n,", ") ); );
%Y A181780
%K nonn
%O 1,1
%A _Karsten Meyer_, Dec 31 2010
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