A105316 Let s denote the 4-symbol substitution 1->{2, 3}, 2->{3, 4}, 3->{}, 4->{1, 3}; let S(1) = 1, and S(n+1) = concat( S(n), s(S(n)) ); then the sequence is S(1), S(2), S(3), ...

1, 1, 2, 3, 1, 2, 3, 2, 3, 3, 4, 1, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 1, 3, 1, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 1, 3, 2, 3, 3, 4, 3, 4, 1, 3, 3, 4, 1, 3, 1, 3, 2, 3, 1, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 1, 3, 2, 3, 3, 4, 3, 4, 1, 3, 3, 4, 1, 3, 1, 3, 2, 3, 2, 3, 3, 4, 3, 4, 1, 3, 3, 4, 1, 3, 1, 3, 2, 3, 3

Offset

0,3

Links

Table of n, a(n) for n=0..104.

Kevin Ryde, PARI/GP Code

Mathematica

s[1] = {2, 3}; s[2] = {3, 4}; s[3] = {}; s[4] = {1, 3};
t[a_] := Join[a, Flatten[s /@ a]];
p[0] = {1}; p[1] = t[{1}]; p[n_] := t[p[n - 1]];
Flatten[Table[p[n], {n, 0, 6}]]

Prog

(PARI) \\ See links.

Crossrefs

Sequence in context: A194899 A228094 A059832 * A105933 A105315 A328912

Adjacent sequences: A105313 A105314 A105315 * A105317 A105318 A105319

Keyword

nonn

Author

Roger L. Bagula, Apr 25 2005

Extensions

Definition of s[4] corrected at the suggestion of Kevin Ryde by Georg Fischer, Mar 20 2024

Definition rewritten at the suggestion of Kevin Ryde - N. J. A. Sloane, Mar 23 2024

Status

approved