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A328991 a(n) = concatenation of a(n-1),2,a(n-2),2,a(n-1), with a(1)=1, a(2)=1221. 3
1, 1221, 12212121221, 1221212122121221212212121221, 122121212212122121221212122121221212122121221212122121221212212121221 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
In the Allombert et al. (2018) paper the sequence starts with a(0) = the empty string.
REFERENCES
Allombert, Bill, Nicolas Brisebarre, and Alain Lasjaunias. "On a two-valued sequence and related continued fractions in power series fields." The Ramanujan Journal 45.3 (2018): 859-871. See W_n in Theorem 2.
LINKS
CROSSREFS
Sequence in context: A091790 A053655 A068262 * A223118 A128655 A251446
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 09 2019
STATUS
approved

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Last modified March 3 17:29 EST 2024. Contains 370512 sequences. (Running on oeis4.)