OFFSET
1,1
COMMENTS
The sequence is periodic: a(91) = a(1). - Georg Fischer, Jan 15 2021
REFERENCES
Clifford A. Pickover, A Passion for Mathematics, John Wiley & Sons, Inc., 2005, pp. 103 and 311 (for "Trains with crystal balls").
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
MATHEMATICA
nxt[n_]:=Module[{idn=IntegerDigits[n]}, 10Total[idn]+Last[idn]+1]; NestList[nxt, 42, 120] (* Harvey P. Dale, Jul 23 2011 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Harvey P. Dale, Jul 23 2011
STATUS
approved