A328992 a(0) = 12; thereafter a(n) is the concatenation of A328991(n),2,A328991(n-1).

12, 122121, 1221212122121221, 1221212122121221212212121221212212121221, 12212121221212212122121212212122121212212122121212212122121221212122121221212122121221212212121221

Offset

0,1

Links

Table of n, a(n) for n=0..4.

Bill Allombert, Nicolas Brisebarre, and Alain Lasjaunias, On a two-valued sequence and related continued fractions in power series fields, arXiv:1607.07235 [math.NT], 2016-2017; The Ramanujan Journal 45.3 (2018): 859-871. See U_n on page 863.

Crossrefs

Cf. A328991, A328993.

Sequence in context: A056540 A331093 A369523 * A069048 A284287 A100246

Adjacent sequences: A328989 A328990 A328991 * A328993 A328994 A328995

Keyword

nonn

Author

N. J. A. Sloane, Nov 09 2019

Status

approved