0,1
No other solutions below 4.10^18 (probably finite) - Dec 15 1999
Table of n, a(n) for n=0..3.
Cf. A028868, A028865, A028866.
Sequence in context: A068708 A063248 A027522 * A179935 A073172 A168139
Adjacent sequences: A028866 A028867 A028868 * A028870 A028871 A028872
nonn,base,hard
Patrick De Geest
approved