0,1

D. Wells, Curious and interesting numbers, Penguin Books, p. 128.

P. De Geest, Nine digits digressions

E.g. n=327 -> 2n=654 -> 3n=981 and 327654981 is a 'nine digit' number.

Cf. A050289.

Adjacent sequences: A039664 A039665 A039666 this_sequence A039668 A039669 A039670

Sequence in context: A084003 A118095 A155843 this_sequence A045077 A030632 A054001

nonn,base,fini,full

Felice Russo (felice.russo(AT)katamail.com)

Corrected by Patrick De Geest (pdg(AT)worldofnumbers.com), Mar 15 2000.