

A160265


Each of the numbers describes the previous number, and is described by the next number.


0



1, 11, 12, 1121, 1321, 123121, 132231, 123222, 112431, 13214131, 14322141, 13423122, 12324123, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241, 12233241
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OFFSET

1,2


COMMENTS

Starting with 1, each of the rest describes the previous number in a "digit + number_of_digits" manner. The oddindexed digits are digits that appeared in the previous term, ordered by the first appearance. The evenindexed digits are how many times that digit appeared. [Edited by Michel Marcus, Oct 26 2021]


LINKS



MATHEMATICA



PROG

(PARI) lista(nn) = {my(v = vector(nn)); v[1] = 1; for (n=2, nn, my(vd = digits(v[n1]), vu = Set(vd), vw = vector(#vu), pos=0, ss=""); for (i=1, #vd, if (!setsearch(Set(vw), vd[i]), pos++; vw[pos] = vd[i]); ); for (i=1, #vw, ss = concat(ss, vw[i]); ss = concat(ss, #select(x>(x==vw[i]), vd)); ); v[n] = eval(ss); ); v; } \\ Michel Marcus, Oct 26 2021


CROSSREFS



KEYWORD

nonn,base


AUTHOR

Adrian Lee (prof.adrian.lee(AT)gmail.com), May 07 2009


EXTENSIONS



STATUS

approved



