1,5

J. O. M. Pedersen, Known Unitary Amicable Pairs

J. O. M. Pedersen, Tables of Aliquot Cycles

Cf. A002952, A002953.

Sequence in context: A062978 A066961 A131549 this_sequence A015784 A129723 A009413

Adjacent sequences: A111901 A111902 A111903 this_sequence A111905 A111906 A111907

nonn,base

N. J. A. Sloane (njas(AT)research.att.com), Nov 24 2005

The next term, a(13), is at least 6664.