1,3

Previous terms can appear in any order but can be used at most once. [From Paolo P. Lava, Mar 04 2010]

Table of n, a(n) for n=1..51.

465 is not in the sequence because 4 U 6 U 5 -> 465

466 is not in the sequence because 4 U 66 -> 466

1313 is not in the sequence because 1 U 313 or 131 U 3 -> 1313

Cf. A141409.

Sequence in context: A071242 A044959 A306273 * A044821 A297148 A048307

Adjacent sequences: A141030 A141031 A141032 * A141034 A141035 A141036

nonn,base

Paolo P. Lava and Giorgio Balzarotti, Jul 30 2008, Aug 04 2008

Corrected by Paolo P. Lava, Mar 03 2010

approved