OFFSET
1,1
COMMENTS
LINKS
Joerg Arndt, Table of n, a(n) for n = 1..1983
Peter Cameron's Blog, Permutation groups and regular semigroups, 2, Posted 22/08/2015.
Michel Marcus, GAP program with issues
PROG
(PARI)
{ forprime(p=11, 10^6,
if ( p%12 != 11, next() );
for (c=2, p-2,
my( v = vector(p-1) );
my( g0 = Mod(c, p), rc0 = znorder(g0) );
if ( rc0 == p - 1, next() );
if ( znorder( -g0 ) == p - 1, next() );
my( g1 = Mod(c-1, p), rc1 = znorder(g1) );
if ( rc1 == p - 1, next() );
if ( znorder( -g1 ) == p - 1, next() );
if ( znorder( g0*g1 ) == p - 1, next() );
if ( znorder( -g0*g1 ) == p - 1, next() );
for (x0 = 0, rc0,
my ( p0 = g0^x0, z = p0 );
for (x1 = 0, rc1,
v[lift(z)] = 1;
v[p - lift(z)] = 1;
z * = g1;
);
);
my( s = sum(k=1, #v, v[k]) );
if ( s < p - 1, print1(p, ", "); break() );
);
); } \\ Joerg Arndt, Mar 20 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Mar 20 2016
EXTENSIONS
Terms > 500 by Joerg Arndt, Mar 20 2016
STATUS
approved