1,1

R. K. Guy, Unsolved Problems in Number Theory, B6.

Christophe CLAVIER, Aliquot Sequences

f := proc(n) option remember; if n = 0 then 180; else sigma(f(n-1))-f(n-1); fi; end:

Sequence in context: A135193 A095650 A066164 this_sequence A015233 A154361 A004532

Adjacent sequences: A008888 A008889 A008890 this_sequence A008892 A008893 A008894

nonn

N. J. A. Sloane (njas(AT)research.att.com).