The Linus sequence is a sequence of 1s and 2s starting with 1. At each step, append the digit that minimizes the length of the longest immediately
repeated block at the end of the sequence (Balister et al. 2010). The first
few terms are 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 2, ... (OEIS A006345).
The Sally sequence gives the length of the run
that was avoided.
Balister, P.; Kalikow, S.; and Sarkar, A. "The Linus Sequence." Combinatorics, Probability and Computing19, 21-46,
2010. https://doi.org/10.1017/S0963548309990198.Sloane,
N. J. A. Sequence A006345/M0074
in "The On-Line Encyclopedia of Integer Sequences."Sloane,
N. J. A. and Plouffe, S. Figure M0126 in The
Encyclopedia of Integer Sequences. San Diego, CA: Academic Press, 1995.
