OFFSET
1,4
LINKS
G. C. Greubel, Table of n, a(n) for the first 8 rows, flattened
EXAMPLE
[1], [1,1,2], [1,1,2,1,2,1,2,1,3], [1,1,2,1,2,1,2,1,3,1,2,1,2,1,3,1,2,1,3,1,2,1,3,1,2,1], ...
MATHEMATICA
NestList[ Flatten[ Join[ #, # /. {1 -> {1, 2}, 2 -> {1, 3}, 3->{1}}]] &, {1}, 4] // Flatten (* Robert G. Wilson v, Jul 09 2006 - corrected by G. C. Greubel, Oct 26 2017 *)
PROG
(PARI) {a(n)=local(m, v, w); v=w=[1]; while(length(w)<n, m=length(v); for(k=1, m, v=concat(v, [[1, 2], [1, 3], [1]][v[k]])); w=concat(w, v)); w[n]} /* Michael Somos, Apr 16 2005 */
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Roger L. Bagula, Mar 26 2005
EXTENSIONS
Image of {3} in the definition corrected by R. J. Mathar, Nov 18 2010
STATUS
approved