OFFSET
1,2
COMMENTS
This is the fixed point of the morphism 0->0231, 1->2310, 2->3102, 3->1023 starting with 0. Let t be the (nonperiodic) sequence of positions of 0, and likewise, u for 1, v for 2, and w for 3; then t(n)/n -> 4, u(n)/n -> 4, v(n)/n -> 4, w(n)/n -> 4. Also, t(n) + u(n) + v(n) + w(n) = 16*n - 6 for n >= 1. See A287556 for a guide to related sequences.
LINKS
FORMULA
a(n) = 4n - A287574(n) for n >= 1.
EXAMPLE
First three iterations of the morphism:
0312
0312203131201203
0312203131201203120303122031312020313120120303123120120303122031
MATHEMATICA
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 31 2017
STATUS
approved