|
|
A300956
|
|
a(0) = 0, a(1) = 2, a(2) = 1, and for any n > 2 with ternary representation n = Sum_{i=0..k} t_i * 3^i, a(n) = Sum_{i=0..k} a(t_i) * 3^a(i).
|
|
3
|
|
|
0, 2, 1, 18, 20, 19, 9, 11, 10, 6, 8, 7, 24, 26, 25, 15, 17, 16, 3, 5, 4, 21, 23, 22, 12, 14, 13, 774840978, 774840980, 774840979, 774840996, 774840998, 774840997, 774840987, 774840989, 774840988, 774840984, 774840986, 774840985, 774841002, 774841004
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
This sequence is a self-inverse permutation of the natural numbers.
This sequence has connections with A300955.
This sequence has infinitely many fixed points (A300958); for any k >= 0, at least one of k or 3^k + 2 * 3^a(k) is a fixed point.
|
|
LINKS
|
|
|
FORMULA
|
a(a(n)) = n.
|
|
PROG
|
(PARI) a(n) = my (t=Vecrev(digits(n, 3))); sum(i=0, #t-1, if (t[i+1]==1, 2, t[i+1]==2, 1, 0) * 3 ^ a(i))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|