OFFSET
0,2
COMMENTS
a(41) > 2.75*10^14. - Giovanni Resta, Jun 04 2013
REFERENCES
P. Tougne, Jeux Mathematiques column, Pour La Science (French edition of "Scientific American"), Vol. 82, Aug. 1984, Prob. 6, pp. 101, 104.
EXAMPLE
a(9)=2 since we have the 9-step chain 2 -> 4 -> 8 -> 16 -> 22 -> 26 -> 38 -> 62 -> 74 -> 102.
MATHEMATICA
f[n_] := Length@ FixedPointList[ # + Times @@ IntegerDigits@# &, n] - 2; t = Table[0, {50}]; k = 1; While[k < 2300000001, a = f@k; If[ t[[a + 1]] == 0, t[[a + 1]] = k; Print[{k, a}]]; k++ ]; t (* Robert G. Wilson v, Jun 27 2010 *)
CROSSREFS
KEYWORD
base,hard,nonn
AUTHOR
Lekraj Beedassy, May 06 2002
EXTENSIONS
Corrected and extended by Jason Earls, May 26 2002
a(34)-a(36) from Robert G. Wilson v, Jun 27 2010
a(37)-a(40) from Giovanni Resta, Jun 04 2013
STATUS
approved