1,1
No other solutions below 2.10^9 (probably finite) - Dec 15 1999
Cf. A028869, A028865, A028866.
Sequence in context: A206591 A003017 A096580 * A081332 A106868 A098419
Adjacent sequences: A028865 A028866 A028867 * A028869 A028870 A028871
nonn,base,hard
Patrick De Geest (pdg(AT)worldofnumbers.com)